Reported Decision : (2004) Aust Torts Reports 81-754 New South Wales Court of Appeal CITATION : Wyong Shire Council v Vairy; Mulligan v Coffs Harbour City Council [2004] NSWCA 247 HEARING DATE(S) : CA40083/03: 20 August 2003 CA40292/03: 17, 18, 20 February 2004 JUDGMENT DATE : 27 July 2004 JUDGMENT OF : Mason P at 1; Beazley JA at 2; Tobias JA at 14 DECISION : Wyong Shire Council v Vairy CA 40083/03; a) Appeal allowed; b) Set aside the orders made by Bell J on 20 December 2002; c) Verdict and judgment for the defendant; d) The plaintiff to pay the defendant's costs of the proceedings and of the appeal but in respect of the latter to have a certificate under the Suitors' Fund Act 1951 if otherwise entitled; Mulligan v Coffs Harbour City Council & Ors CA 40292/03; a) Appeal dismissed with costs CATCHWORDS : TORTS - Negligence - Personal injury - Scope of duty of care - Reasonable response - Obvious Danger - Inherent danger - Duty to warn - Unknown and variabe depth - Diving accident - TORTS - Negligence - Personal injury - Existence of duty - Contributory negligence - Causation - Apportionment - Damages - Volenti - PRACTICE & PROCEDEURE - Fairness - Raising argument post-appeal - Not run at trial - Not argued on appeal Civil Liability Act 2002 (NSW) LEGISLATION CITED : Law Reform (Miscellaneous Provisions) Act 1946 (NSW) Law Reform (Miscellaneous Provisions) Act 1965 (NSW) Ah Tong v Wingecarribbee Council [2003] NSWCA 381 Beck v State of New South Wales [2001] NSWSC 278 Berryman v Joslyn; Wentworth Shire Council v Joslyn [2004] NSWCA 121 Brodie v Singleton Shire Council (2001) 206 CLR 512 Bucheleres v The Chicago Park District (1996) 665 N.E. 2d 826 Burns v Hoyts Pty Ltd [2002] Aust Tort Reports 81-637 Canterbury Municipal Council v Taylor [2002] NSWCA 24 Chappel v Hart (1998) 195 CLR 232 City of Rockingham v Curley (2000) 112 LGERA 123 Darby v The National Trust [2001] PIQR P372 Diamond v Simpson (No. 1) [2003] Aust Torts Rep 81-695 Dovuro Pty Ltd v Wilkins (2003) 77 ALJR 1706 Dowen v Hall (1989) 548 N.E. 2d 346 Francis v Lewis [2003] NSWCA 152 Ghantous v Hawkesbury City Council (2001) 206 CLR 512 Griebler v Doughboy Recreational, Inc (1991) 466 N.W 2d 897 Hadland v Council of the City of Blacktown, Court of Appeal (unreported) 21 May 1997 Hagy v McHenry County Conservation District (1989) 546 N.E. 2d 77 Harriton (by her tutor) v Stephens; Waller (by his tutor) v James; Waller (by his tutor) v Hoolahan [2004] NSWCA 93 Hastings Council v Giese [2003] NSWCA 178 at [18]; Hoyts Pty Ltd v Burns (2003) 201 ALR 470 Insurance Commissioner v Joyce (1948) 77 CLR 39 and Inverell Municipal Council v Pennington (1993) 82 LGERA 268 Jackson v TLC Associates (1998) 706 N.E. 2d 460 Jeffries v Fisher [1985] WAR 250 Moore v Woodforth [2003] NSWCA 9 Mulligan v Coffs Harbour City Council [2003] NSWSC 49; (2003) Aust Torts Reports 81-689 Nagle v Rottnest Island Authority (1993) 177 CLR 423. CASES CITED : National Insurance Co of NZ Limited v Espagne (1961) 105 CLR 569 Nominal Defendant v Gardikiotis (1996) 186 CLR 49 O'Sullivan v Shaw (2000) 726 N.E 2d 951 Podrebersek v Australian Iron & Steel Pty Limited (1985) 59 ALJR 492 Prast v Town of Cottesloe (2000) 22 WAR 474 Public Trustee as Administrator of the Estate of the later Peter Saroukas v Sutherland Shire Council (1992) Aust Torts Report 81-149 Redding v Lee; Evans v Muller (1983) 151 CLR 117 Rhind v Ashbury Water Park Limited & Anor [2003] EWHC 1029 (QB) Roads & Traffic Authority of NSW v Jackson [2003] NSW CA 40 Rogers v Whitaker (1992) 175 CLR 479 Roggenkamp v Bennett (1950) 80 CLR 292 Romeo v Conservation Commission of the Northern Territory (1998) 192 CLR 431 Rosenberg v Percival (2001) 205 CLR 434 Sara v Government Insurance Office of New South Wales (1969) 89 WN (Pt 1) (NSW) 203 Secretary to the Department of Natural Resources & Energy v Harper [2000] 1 VR 133 Snilsberg v Lake Washington Club (2000) 614 N.W 2d 738 Tame v New South Wales (2002) 211 CLR 317 Tomlinson v Congleton Borough Council [2004] 1 AC 46 Turner v South Australia (1982) 56 ALJR 839 University of Wollongong v Mitchell [2003] NSWCA 94 UTSA Pty Ltd (in liq) v Ultra Tune Australia Pty Ltd (1996) 21 ACSR 457 Van Der Sluice v Display Craft Pty Ltd [2002] NSWCA 204 Van Gervan v Fenton (1992) 175 CLR 327 Waverley Council v Lodge (2001) 117 LGERA 447 Waverley Municipal Council v Swain [2003] NSWCA 61 Whyte v Redland Aggregates Ltd (unreported) 27 November, 1997; Court of Appeal (Civil Division) Woods v Multi-Sport Holdings Pty Ltd (2002) 208 CLR 460 Woolcock Street Investments Pty Limited v CDG Pty Limited [2004] HCA 16 Wyong Shire Council v Shirt (1980) 146 CLR 40 Wyong Shire Council v Vairy [2002] NSWSC 881; (2002) 129 LGERA 10 CA40083/03: Wyong shire Council; Ernest Vairy. CA40292/03: Garry Mulligan; PARTIES : Coffs Harbour City Council; State of New South Wales; Coffs Harbour Jetty Foreshore Reserve Trust; Wal Hambly. FILE NUMBER(S) : CA 40083/03; 40292/03 CA40083/03 A: Mr I G Harrison SC / Mr D Villa R: Mr C C R Hoeben SC / Mr E Muston COUNSEL : CA40292/03 A: Mr G O'L Reynolds SC / Mr J B Meadley / Mr R Foord 1R: Mr M T McCulloch / Mr D Villa 2R: Mr J E Maconache QC / Mr Green CA 40083/03 A: Minter Ellison R: Carroll & O'Dea SOLICITORS : CA40292/03 A: Martin Bell & Co 1R: Phillips Fox 2R, 3R & 4R Crown Solicitor LOWER COURT Supreme Court JURISDICTION : LOWER COURT ED 13576/93 FILE NUMBER(S) : SC 20113/00 LOWER COURT CA40083/03: Bell J; CA40292/03: Whealy J JUDICIAL OFFICER : IN THE SUPREME COURT OF NEW SOUTH WALES COURT OF APPEAL CA 40083/03 ED 13576/93 CA 40292/03 SC 20113/00 MASON P BEAZLEY JA TOBIAS JA Tuesday 27 July 2004 WYONG SHIRE COUNCIL v ERNEST VAIRY GARRY MULLIGAN v COFFS HARBOUR CITY COUNCIL After hearing both appeals separately the same bench brought down a single judgment. The first appeal concerned Mr Vairy (the respondent) who was rendered quadriplegic after diving off a rock platform into the sea at a popular Central Coast beach. He had never dived from the platform before although he had seen many others do so on previous occasions without mishap, including immediately prior to his dive. The water's depth could not be ascertained from Mr Vairy's position on the platform and he took no steps to determine its depth before diving. Wyong Council (the appellant) who had the care, control and management of the platform was aware of the use of the platform. Further, they were aware that the seabed in that vicinity was subject to variation as sands moved up and down the coast. However, no steps were taken to warn of the dangers of (or perhaps prohibit) diving. The evidence also revealed that Mr Vairy's former uncle-in-law had suffered sever spinal injuries in a diving accident years earlier at another location. The primary judge held that the Wyong Council owed Mr Vairy, a legal entrant onto the platform, a duty of care as an occupier. Further, that it was reasonably foreseeable that a person in Mr Vairy's position might not appreciate (as Wyong did) that, due to seabed variation, the water was not necessarily sufficiently deep: a risk only heightened by seeing others diving safely on other occasions. This risk was found to be a hidden one and that, as such, a reasonable response was to either warn of such danger, or prohibit diving. By failing to do this Wyong Council breached its duty of care. Mr Mulligan, the appellant in the second appeal, was rendered quadriplegic after he dived forward into a submerged bedform from a standing position in thigh deep water at a creek in Coffs Harbour. He had never swum in the creek before, but for the previous half hour he had been wading out to the middle of the creek and diving forward into the current to be carried downstream. His injury occurred on approximately his sixth repetition of this activity. The bottom of the creek was not visible and, while being aware of the variability in depth due to the presence of bedforms, he was unaware of the depth of water into which he dived. Coffs Harbour City Council, the State and to a lesser degree the Trust (the respondents) had, in accordance with their statutory powers enhanced the creek - a popular recreational location - over several decades. At the time of the injury several others were either swimming in the creek (some engaging in similar activity to the appellant) or recreating on its banks, predominantly the northern bank. The evidence revealed that the presence of bedforms in the creek would naturally vary with the ebb and flow of the creek's tides. The primary judge found that while the respondents, as occupiers, owed Mr Mulligan a duty of care as an entrant, and while the risk of injury arising from the striking of a transient dune was reasonably foreseeable, the scope of the duty did not require that Mr Mulligan be warned of the danger of diving since the danger of striking such a dune when diving was both obvious and inherent. The appeal primarily focused upon, and was ultimately determined by, the scope of the owed duties of care. Several other issues, not strictly determinative of the appeal, were considered by the Court, these included: (common to both appeals) causation and contributory negligence; and (exclusive to Mulligan) the ability of a party to raise issues post-appeal which had neither been raised at trial or in oral argument on appeal, whether all the respondents owed a duty of care, if the defence of volenti was made out, and if damages had been calculated correctly. HELD (Tobias JA, with Mason P agreeing and Beazley JA agreeing in respect of Mulligan and in dissent regarding breach of duty in Vairy): 1. A danger is obvious where both the condition and the risk are, in the individual circumstances of the case, apparent to, and would be recognised by, a reasonable person in the position of the plaintiff exercising ordinary perception, intelligence and judgment. [161] 2. In the present case the risk or danger facing the respective plaintiffs was the risk of significant injury resulting from diving into water of unknown and variable depth, which turned out to be too shallow. [197] 3. In Vairy the primary judge erred by defining the risk (that it was not apparent to a diver on the platform that the water may not be sufficiently deep) at too narrow a level of abstraction. [146] & [199] 4. In Mulligan the risk was defined as that of striking a transient naturally occurring on the bed of a tidal creek of variable depth. To this must be added the fact that the water was of unknown depth. [200] 5. These dangers, in the circumstances, were obvious dangers. [201], [211] 6. In the application of the Shirt calculus the fact that a danger is obvious is merely one factor to be considered when determining the scope of the owed duty. However, in a given circumstance, the presence of an obvious danger may be determinative especially where the only breach alleged is a failure to warn. [72]-[73], [168], [195] 7. In the present cases the circumstances were such that the knowledge of the occupier-defendants (actual or assumed) was neutralised by the obviousness of the risk of injury attaching to diving into water of variable and unknown depth which risk was apparent to the plaintiffs. In these circumstances the scope of the occupier-defendants' duty did not involve a duty to warn or prohibit diving. [206] 8. The fact that the plaintiff in Vairy had seen others dive without mishap on numerous occasions, and that the plaintiff in Mulligan had himself executed a similar dive safely on immediately preceding occasions, did not neutralise or otherwise detract from the obvious risk of diving into water of unknown and variable depth. [210] 9. In Vairy this finding was accentuated by the plaintiff's knowledge of his former uncle-in-law's diving injury. [211] 10. In the circumstances the failure to warn, or to take any other steps, did not constitute a breach of any owed duty of care. In both cases the plaintiffs failed to take proper care for their own safety in the face of a risk that was obvious in the circumstances. [202], [209], [215] OTHER FINDINGS: 1. A party on appeal is not at liberty to raise without leave, post-appeal, an argument not in issue in the court below or raised in oral argument on appeal. [226] 2. In Vairy and Mulligan the primary judge's findings regarding causation were not in error. [249], [296] 3. In Vairy the primary judge, by failing to give significant weight to factors relevant to the plaintiff's contributory negligence, fell into error. The plaintiff's contributory negligence should be 55%. [257] 4. In Mulligan the primary judge was correct in finding that Coffs Harbour City Council owed the plaintiff a duty of care due to the extent of its care, control and management of the area surrounding the creek and through its power to erect warning signs. The State, through its active managing role, created a relationship that likewise gave rise to a duty of care. [275] 5. In Mulligan the primary judge was correct to find that the plaintiff did not fully comprehend the nature and extent of the relevant risk such that the defence of volenti was established. [312] 6. In Mulligan the primary judge's findings of contributory negligence were not outside the applicable range in that they were neither unreasonable nor unjust. [320] 7. In Mulligan the primary judge's discretion in respect of apportionment miscarried. In the circumstances it would be just and equitable for contribution between Coffs Harbour City Council and the State to be 50% each. [331] 8. In Mulligan the primary judge, when determining damages, was not in error to find that the defendants should not receive credit for the rent the plaintiff has been receiving from his own house while he has been living at his parent's house post-accident. In the circumstances the plaintiff ought not to be made worse off because he has decided to rent a property in which, but for the accident, he would have resided. [344] Per Beazley JA in dissent regarding breach of duty in Vairy: 1. Notwithstanding the fact that diving from a rock into the ocean is inherently dangerous, the primary judge was not in error to conclude that the appellant breached its duty by failing to erect warning signs in circumstances where: firstly, the depth of water could not accurately be gauged by observation; secondly, most people assessed the risk of diving by the observation of others; and thirdly, the local life guards occasionally warned people against jumping and diving. Such a conclusion was in accordance with High Court authority. [12] IN THE SUPREME COURT OF NEW SOUTH WALES COURT OF APPEAL CA 40083/03 ED 13576/93 CA 40292/03 SC 20113/00 MASON P BEAZLEY JA TOBIAS JA Tuesday 27 July 2004 WYONG SHIRE COUNCIL v ERNEST VAIRY GARRY MULLIGAN v COFFS HARBOUR CITY COUNCIL 1 MASON P: I agree with Tobias JA. 2 BEAZLEY JA: I have had the advantage of reading, in draft, the judgment of Tobias JA. Given his Honour's comprehensive review of both the facts and the law it is only necessary for me to state briefly my point of departure from his Honour's decision in relation to the respondent, Ernest Vairy. I otherwise agree with his Honour's reasons and agree with his proposed orders in relation to the matter of Mulligan. 3 In Vairy, for my part, I see no error in the trial judge's findings of fact, the application of the law to those facts or in her reasoning process. Her Honour recounted, in detail, the evidence of Mr. Vairy and the various witnesses. That evidence requires a short review. 4 Mr. Vairy had been a frequent visitor to Soldiers Beach, where his accident occurred, in the years leading up to his accident. He was an experienced swimmer, and had swum and snorkelled at Soldiers Beach, including on the day before his accident. He had frequently seen visitors to the beach jumping and diving off the rock platform into the ocean. 5 The appellant had a policy of encouraging visitors to its area, including the recreational beaches in its local government area. Soldiers Beach was one of the popular recreational swimming areas in the locality, although it was uncertain whether there had been any specific promotion of it by the appellant. The beach was patrolled by surf lifesavers both during the week and on weekends. Officers of the Council provided some of the lifesaving patrols. The local lifesaving club conducted the weekend patrols. The lifeguards both from the Council and the Club were aware that people both jumped and dived from the platform. 6 Relevantly, some twenty years previously, there had been a serious injury when a user of the beach had become a paraplegic when he jumped into the water from the rocks at the northern end of the beach – although it appears he jumped from a place higher than the place from which Mr. Vairy dived. 7 There was a newspaper report at the time stating that the Beach Inspector, Mr. Edwards, proposed to recommend to the appellant that a "Danger: No Diving" sign be erected on the rock platform. Mr. Edwards said in these proceedings that he did not remember speaking to a journalist but agreed he may have done so. He appears to have accepted however that he had considered that there should be a warning sign erected. He said: "There were obvious dangers of diving off a rock into water, but the thing that concerned me most is probably the hidden danger of the fact that the water can vary in depth with sand movement. There are rocks below the surface. I think there are issues there that if you just walked up and looked over the edge of the high rock, there are things there that you may not necessarily be aware of unless you went and tested the water first". 8 Mr. Edwards said these dangers extended along the length of the rock platform. 9 A number of persons who had regularly dived from various parts of the rock platform gave evidence. Of particular relevance was their evidence that they assessed the safety or otherwise of diving by reference, inter alia, to whether other people were diving from it. They also said it was not possible to gauge the depth of the water from the rock platform, although generally the ocean floor was visible. The trial judge made a finding of fact that the respondent assumed it was safe to dive from the rock platform because, amongst other things, he saw other people diving from it. 10 The Soldiers Beach Surf Life Saving Club, which patrolled the beach on the weekend, was concerned about swimmers jumping and diving off the rock. Mr. Jones, an experienced lifeguard with the Club, said that during summer holidays anything from one to thirty people could be jumping or diving from the rock platform. The Club warned people from time to time by going over to the area in a rubber dinghy telling intending jumpers not to jump because there had been the previous serious accident when "a young man jumped off here and became a paraplegic". He said such warnings were usually peremptorily ignored. 11 The above is but a brief summary, but it and the other facts found by he trial judge established the following. The danger caused by the changing depth of the ocean floor was a naturally occurring phenomenon. The appellant did not create it. The beach was a popular recreational beach and the activity engaged in by the respondent, namely, diving from part of the rock platform at the northern end of the beach, was a common activity as was known to the appellant. That activity was dangerous and could result in serious injury, as was also know to the appellant. The respondent was aware of the possible serious consequences of a dive because a relative of his former wife had suffered a severe spinal injury as a result of a diving accident. 12 Whilst it is correct to say that diving from a rock into the ocean is inherently dangerous, there were two factors here of particular relevance. The first was that it was not possible to gauge the depth of the water by observation from the rock platform. The second is that there was evidence that most people who dived from that location assessed the risk in doing so by reference to whether other people were diving. When those two factors are taken in conjunction with the fact that the life guards from time to time warned people not to jump, it seems to me, that upon a proper application of the principles in Nagle and Romeo, as discussed by Tobias JA, her Honour's conclusion, that the appellant breached its duty by failing to erect warning signs, was open to her. It is a conclusion with which I would agree. There is nothing, in my opinion, in the later authorities in the High Court, discussed by Tobias JA, which requires a contrary conclusion. If anything, the remarks of the Chief Justice in Woods v. Multi-Sport Holdings Pty. Limited (2002) 208 CLR 460; [2002] HCA 9 at [45] that "What reasonableness requires by way of warning from an occupier to an entrant is a question of fact, not law, and depends on all the circumstances, of which the obviousness of a risk may be only one. And, as a proposition of fact, it is not of universal validity. Furthermore, the description of a risk as obvious may require closer analysis in a given case. Reasonableness would not ordinarily require the proprietor of an ice skating rink to warn adults that there is a danger of falling; but there may be some skaters to whom such a warning ought to be given." underscore the correctness of her Honour's approach. 13 I should also add that I would not interfere with her Honour's assessment of contributory negligence: see Podrebersek v Australian Iron & Steel Pty Limited (1985) ALJR 492. 14 I would dismiss the appeal in Vairy with costs. 15 TOBIAS JA: In coastal New South Wales and, no doubt, in other coastal areas of Australia, public authorities such as local government councils have the care, control and management of ocean beaches, tidal creeks and estuaries. Members of the public enter these areas as of right for various recreational purposes including swimming and surfing. In many cases the public authority encourages, actively or passively, and/or promotes the use of its beaches and creeks for those purposes. It is part and parcel of those activities that people dive into the water from natural features such as rock platforms as well as from a standing or running position in the water itself. 16 So it was that the plaintiffs in the present cases visited, in the case of Mr Vairy, Soldiers Beach in Wyong Shire and, in the case of Mr Mulligan, Coffs Harbour in Coffs Harbour Shire. Both intended to swim and both also decided to dive. Mr Vairy decided to dive into the water from a natural rock platform at the northern end of Soldiers Beach at a point found to be 1 to 1.5 metres above the surface of the water. He had not dived from the rock platform before but had seen others doing so without mishap. Mr Mulligan decided to dive from a standing position in the creek where the water level reached mid-thigh; he had successfully dived from approximately the same location on approximately six occasions. Each man then executed a dive with tragic consequences. Each struck his head on the sandy bottom and suffered a broken neck. Mr Vairy sustained irreversible tetraplegia and Mr Mulligan irreversible quadriplegia. To all intents and purposes their lives were seemingly ruined. 17 Each no doubt feels that fate has dealt with him most unfairly. Each sued the public authorities having the care, control and management of Soldiers Beach and Coffs Creek respectively seeking financial compensation for loss of earning capacity, the expense of the care each will require and the considerable loss of their ability to lead a normal life which, in many respects, was full of promise. To acknowledge one's sympathy with their predicament would be an understatement. 18 However, as Lord Hoffman recently reminded us in Tomlinson v Congleton Borough Council [2004] 1 AC 46 at 72 [4], "the law does not provide such compensation simply on the basis that the injury was disproportionately severe in relation to one's own fault or even not one's own fault at all. Perhaps it should be, but society might not be able to afford to compensate everyone on that principle, certainly at the level at which such compensation is now paid. The law provides compensation only when the injury was someone else's fault" In order to succeed in their claims, therefore, that is what Mr Vairy and Mr Mulligan were required to prove. 19 The proceedings in Wyong Shire Council v Vairy [2002] NSWSC 881; (2002) 129 LGERA 10 (Vairy) were heard by Bell J who, on 20 December 2002, found that the defendant was in breach of its duty of care and entered judgment for the plaintiff in the sum of $5,054,753.25. The proceedings in Mulligan v Coffs Harbour City Council [2003] NSWSC 49; (2003) Aust Torts Reports 81-689 (Mulligan) were heard by Whealy J who, on 14 March 2003, found there was no such breach and entered judgment for the defendants. Had he found for the plaintiff, his Honour would have awarded damages in a sum exceeding $9,000,000. The defendant in Vairy and the plaintiff in Mulligan appeal to this Court against those decisions The hearing of the appeals 20 Although the appeals were not heard together, they raise similar issues for determination and have, therefore, been heard by the same bench. In particular, they raise the important question of whether a public authority having the care, control and management of a natural aquatic area such as an ocean beach or tidal creek, will be in breach of its duty of care to an adult member of the public who voluntarily dives into water of unknown but variable depth where the authority has failed to erect a sign or signs warning of the danger of diving in those circumstances. 21 The difficulty of resolving this issue is illustrated by the fact that in one case the plaintiff succeeded and in the other he failed. This is not to say that out of some necessity, based upon general factual similarities, both plaintiffs must either have succeeded together or failed together. Given the individuality of a particular case it is conceivable that both first instances decisions could have been correct. The point to be made is that the issues thrown up by the two cases do involve points of considerable difficulty and that the level of difficulty is simply made all the more evident by the differing outcomes at first instance where the cases did share notable factual similarities but did not exhibit notable factual differences. 22 In both cases the relevant public authorities were aware that people dived into the waters in question. In both cases the depth of the water into which the plaintiffs dived was variable due to the natural movement of the sand bed. In neither case could the depth of the water be accurately determined by visual observation, a fact known to each plaintiff and to the authorities. In both cases the plaintiffs assumed that the water was sufficiently deep for their dive to be executed safely: in the one case because the plaintiff had seen others dive from the same rock platform without mishap; and in the other because the plaintiff had seen others in the vicinity dive safely and had done so himself on a number of occasions before the dive that resulted in his injuries. In both cases the plaintiff sustained a broken neck with consequent quadriplegia. And in both cases the plaintiff relied heavily on the decision of the High Court in Nagle v Rottnest Island Authority (1993) 177 CLR 423. 23 In one sense the primary issue in each case of breach of duty involves no more than an application of the test enunciated by Mason J in Wyong Shire Council v Shirt (1980) 146 CLR 40, 47-48 (the Shirt calculus). But the very balancing exercise called for by that test, when taken in conjunction with later decisions of the High Court and this Court, makes it apparent that that exercise involves, at least in some respects, policy considerations of some significance. 24 In particular, the balancing exercise called for by the Shirt calculus involves consideration of whether, all things being equal, a public authority should be liable in negligence for failure to warn of conditions brought about by natural phenomena such as the movement of waves and/or the ebb and flow of the tide. In these circumstances, should not a person who engages with the natural conditions of the ocean or a tidal creek for the purposes of recreation accept often inherent and obvious risks of injury associated with his or her activities as part of the price of enjoyment of the activity undertaken? These are difficult questions to answer where, in terms of the Shirt calculus, the magnitude of the risk of catastrophic injury is high but the degree of probability of its occurrence based, at least, on past experience, is low. It is made even more difficult by the fact that, generally speaking, the erection of an appropriate warning sign or signs at the particular location is simple and inexpensive and would have been so in the present cases. Wyong Shire Council v Vairy – the facts 25 At the northern end of Soldiers Beach within the area of Wyong Shire Council (Wyong) lies a headland separating Soldiers Beach from Pebbly Beach. Around the base of the headland is a substantial rock outcrop. Extending into the sea from the southern end of the rock outcrop is a finger-like expanse of rock of varying heights above the surface of the water (the rock platform). Mr Vairy suffered his injuries when, on 24 January 1993, he dived into the water from a position on the eastern side of that platform. 26 At the time of the accident Soldiers Beach was a popular surfing and recreation spot. Wyong had provided a number of amenities including a substantial bituminised public car park at the top of the northern headland from which both the beach and rock platform could be accessed. Relevantly, the rock platform was accessible by a set of low wooden steps, which joined a gravel path. This path led to the rocks at the base of the headland near the point where the rock platform commenced its extension into the sea. 27 Other amenities provided by Wyong included a kiosk adjacent to the car park, two other car parks and a substantial clubhouse occupied by the local surf club. 28 In 1993 Soldiers Beach was one of six patrolled beaches under the care, control and management of Wyong. On weekdays it was patrolled by lifeguards employed by Wyong while on weekends volunteer lifesavers assumed the patrolling responsibilities. It was Wyong's policy at the time of the accident to promote tourism by encouraging members of the public to visit the patrolled beaches within its Shire including Soldiers Beach. It was aware at all relevant times that the car park located on the northern headland enabled the public to gain access more readily to a number of points on the coastline including the rock platform. 29 At the time of the accident, Mr Vairy had been living near Soldiers Beach for approximately four years. He was aware that his former wife's uncle had suffered a severe spinal injury as a result of a diving accident on the Nepean River several years before he and his former wife were married. He was a physically active man who participated in a number of sports but, this notwithstanding, the primary judge accepted that he was a person who did not take risks and who was safety conscious. In the four years leading up to the accident, Mr Vairy had frequented Soldiers Beach in the summer to engage in swimming, snorkelling and fishing. He recalled seeing people traverse the gravel path that led from the car park to the rock platform and observed people diving and jumping from the rock platform. The primary judge found that for many years prior to January 1993, the rock platform had been a popular place for people to congregate during the summer months and that it was common for people of various ages to jump and dive into the ocean from that platform. However, on no occasion prior to the accident had Mr Vairy himself ever dived from the platform into the sea. 30 Importantly, Mr Vairy had never previously made an assessment of the depth of the water adjacent to the location from which he dived. On the day prior to the accident, when snorkelling off the western side of the southern tip of the rock platform, he had duck-dived in an attempt to pick up an object lying on the seabed and although he was not able to recall how deep the water was on this occasion, he thought it was "a fair way down". 31 On the day of the accident Mr Vairy, with members of his extended family, entered the surf for a swim. His young niece wished to visit the rock platform and Mr Vairy agreed to accompany her. The platform was visible from where they stood and people could be seen jumping and diving from it. He recalled that as he approached the rock platform he had it in mind to dive from it. Upon arriving at the platform, he and his niece spent approximately five minutes standing and watching people diving, jumping and bombing into the water from it. 32 While the seabed was visible from the point on the rock platform from which he dived (the dive location), Mr Vairy took no steps to assess the water's depth at that point. Instead, he assumed that it was safe for him to dive. The reasons for his assumption were two-fold: firstly, because he had seen others dive in the five minutes leading up to his own dive; and secondly, because he had seen others dive from the rock platform over the years that he had been visiting Soldiers Beach and on no occasion had he seen anyone sustain an injury from doing so. 33 Having assumed that diving from the rock platform was safe, Mr Vairy did so and was injured. The primary judge accepted that he sustained his injuries because he hit his head on the ocean floor. She further found that it was not suggested that Mr Vairy had executed a vertical or otherwise inherently dangerous style of dive. Her Honour concluded that Mr Vairy hit the ocean floor because the water was not sufficiently deep to admit a dive at a 45° angle being safely executed by an adult male of his height. 34 The primary judge also found that at the time of the accident the sea was calm with only a little surge. However, notwithstanding a deal of expert evidence, her Honour was unable to determine the depth of water at the dive location. However, she was able to conclude that the distance between the water surface and the dive location was greater than 1 metre and more likely as much as 1.5 metres. 35 It was common ground that before he dived, Mr Vairy did not seek to observe the depth of the water in any meaningful way. In fact he gave evidence that he could not see the seabed from where he stood (which was slightly back from the edge of the rock platform) prior to his dive. However, he thought it "looked deep enough" because it was a deep shade of blue. The primary judge found that Mr Vairy could have seen the ocean floor had he looked but, of course, he did not. However, as I have already observed, visual observation would not have permitted an accurate determination of the depth of the water due, no doubt, to the effect of the refraction of light. 36 There had been a previous diving accident in the general location (in January 1978) when a Mr von Sanden had suffered irreversible tetraplegia after diving off a section of the rock platform known as the "high rock". It would appear that the "high rock" was located some distance to the north of the location from which Mr Vairy dived. It was surveyed at 5.27 metres AHD compared to Mr Vairy's dive location, which was between two points surveyed as 1.91 metres and 3.03 metres AHD. There was a localised but large response to Mr von Sanden's accident and it was established that Wyong was aware of it. Notwithstanding that knowledge, Wyong took no steps to either prohibit people from diving from any part of the rock platform or to warn of the dangers of so doing. 37 There was also evidence that there were other accidents (approximately one injury each year) associated with the rock platform, resulting in dislocations, cuts and fractures. Members of the local surf life saving club had warned people of the dangers of jumping off the rock platform, sometimes by going over to it in the club's "rubber ducky". However, the response to such warnings was typically negative. There was no finding by the primary judge that Wyong was aware of these incidents. 38 As I have noted, the primary judge found that although the seabed could be seen from the rock platform, one could not accurately assess the depth of water at that location. Her Honour thus found that the risk that the water on any given occasion was not sufficiently deep to making diving safe was not necessarily apparent to a person standing on the rock platform at the dive location and looking into the water. 39 The expert evidence established that the movement of sand along the coast was particularly pronounced around rock headlands such as the rock platform. The depth of water at the rock platform would therefore change due to the build up of sand and the tide. The primary judge found that Wyong knew or ought to have known that the ocean floor adjacent to the rock platform would vary in depth as a result of the significant movements in sand along the eastern coast and that those variations in the level of the seabed posed a danger for persons diving from the rock platform. In particular, she identified the danger as being one whereby persons who had previously dived with safety may have been misled by the belief that the depth of water would be sufficient to allow safe diving and that persons such as Mr Vairy, who had observed people diving safely on other occasions, might be misled into thinking that the water was sufficiently deep to dive when it was not. 40 So far as the erection of an appropriate sign was concerned, there was no suggestion that the erection of such a sign in the immediate locality would be a drain on Wyong's financial resources. However, concern was expressed with respect to the practicality and cost of erecting warning signs (as to a variety of dangers) along the 27 km of coastline, which Wyong controlled. 41 The primary judge held that Wyong owned to Mr Vairy a duty to take reasonable care to avoid a foreseeable risk of injury being occasioned to him. In so holding, her Honour applied the High Court's decisions in Nagel and Romeo v Conservation Commission of the Northern Territory (1998) 192 CLR 431. However, the real issue confronting her was the scope of the relevant duty of care and whether it had been breached. 42 The primary judge then referred to the passage in the judgment of Kirby J in Romeo at 478 [123] where his Honour held that where the statutory duties of the relevant public authority are stated in general and permissive terms (as in the present case), the scope of the duty of care imposed by the common law will be no more than that of reasonable care so that where a risk is obvious to a person exercising reasonable care for his or her own safety, the notion that the authority must warn with respect to that risk was neither reasonable nor just. Her Honour considered that the obviousness (or otherwise) of the risk was relevant to her determination of the content of the reasonable response of Wyong to what she had held to be a foreseeable risk of injury. 43 On the breach issue, the primary judge, after stating the Shirt calculus, expressed her satisfaction that the danger of a person sustaining severe injury as a result of diving from the rock platform was foreseeable, it being neither far-fetched nor fanciful to consider that a person so diving might sustain severe injury. After noting that Wyong did not contend to the contrary, her Honour further found that the erection of signs prohibiting diving or, at least, warning of the dangers of diving from the rock platform would have occasioned relatively little expense to it. 44 After citing from the joint judgment in Nagel at 429-430 and from a number of other authorities to which I shall return, the primary judge made the following findings: a) the facilities provided by Wyong encouraged members of the public to make use of the rock platform as well as the beach; there was no distinction in terms of the nature of that encouragement between that in the present case and that found by the High Court in Nagle ; b) the rock platform from which Mr Vairy dived was a distinct and unusual natural formation adjoining the beach and readily accessible to members of the public and, to Wyong's knowledge, provided an attractive, popular and ready means of entering the ocean by diving, jumping or bombing; c) diving from any position along the rock platform was dangerous in that it was attended by a real risk that the diver would strike the ocean floor and thereby suffer injury; d) the risk for a person diving from the rock platform was greater on some days than on others by reason of the movement of sand leading to significant variations in the depth of the ocean floor; e) although the ocean floor was generally visible, it was not possible to accurately gauge the depth of the water from the rock platform; f) the risk that the water on any given occasion was not sufficiently deep to make diving safe was not necessarily apparent to a person standing on the rock platform at the dive location and looking into the water; g) the fact that it was common for people to dive from the rock platform was likely to lead others to consider that it was safe to do so; however on some occasions it would be safe and on others it would not; h) Wyong knew or ought to have known that the ocean floor adjacent to the rock platform varied in depth as a result of the significant movements of sand along the eastern coast; it also knew or ought to have known of the danger that the variation in the level of the seabed posed to persons diving from the rock platform; i) in addition to the general difficulty of estimating the depth of the water, the relevant dangers were: firstly, that persons who had previously dived with safety may be misled by the belief that the depth of water would be sufficient to allow safe diving and, secondly, persons such as Mr Vairy who had observed people diving safely on other occasions may be misled into thinking the water was sufficiently deep to dive safely when it was not; j) Wyong was armed with knowledge that Mr Vairy did not have concerning the danger of diving from the rock platform in that it knew or ought to have known that there could be significant variations in the depth of the water adjacent thereto so that a dive might safely be executed on one day but not the next; k) the fact that it was relatively common for people to dive from the rock platform detracted from any contention that the risks of doing so were apparent such that it was reasonable for Wyong to take no action to warn the public of them; l) accordingly, the risk of sustaining severe injuries by diving from the rock platform was not of such an obvious nature that the reasonable response of Wyong was to take no steps to warn of it; m) it followed that the reasonable response of Wyong to a risk of that magnitude required it to take steps to eliminate or reduce the danger by erecting signs prohibiting diving from the rock platform or warning of the danger of doing so at the access points thereto. 45 I shall, for the moment, put to one side Bell J's findings on causation and contributory negligence. I turn now to the facts as found by Whealy J in Mulligan and to his Honour's conclusions with respect to scope and breach of duty in that case. Mulligan v Coffs Harbour City Council – the facts 46 Coffs Creek runs through the centre of the town of Coffs Harbour before spilling, albeit shallowly, into the sea at Park Beach at a point some 500 metres or so north of the harbour. Approximately 300 metres west of the beach two bridges cross a 30-metre span of the creek. The most westerly of these is known as the Orlando Road Bridge whereas the one to east and running parallel is known as the Railway Bridge. 47 The creek to the east of the bridges had been a popular swimming location since the 1970's. In particular, a section of the northern bank was a popular swimming location for children and their families – the use of which had been enhanced by the construction by Coffs Harbour Shire Council (Coffs Harbour) of two rock training walls that had been extended from time to time. The purpose of the training walls was to direct the flow of water in the creek so as to reduce the erosion of sand from the beach comprising the northern bank of the creek. 48 The beach upon the northern bank adjoined a grassed area retained by a timber wall constructed by Coffs Harbour. That grassed area contained a number of facilities such as BBQ, picnic and changing rooms, toilets and the like, which were accessible from a nearby public car park. The foregoing area was Crown land known as Park Beach Reserve, the trustee of which was Coffs Harbour. It was common ground that the latter had the care, control and management of this area the southern boundary of which extended to the northern mean low water mark of the creek. 49 In contrast the southern bank of the creek, although sandy and attractive, was not developed. Access to the beach comprising the southern bank was achieved by way of a short, well-used dirt track (the dirt track) that branched off a paved walkway/cycleway (the walkway) a few metres east of the railway bridge. The walkway commenced on the eastern side of Orlando Street, a short distance west of the Orlando Street Bridge, proceeded down an embankment to a point on the southern bank of the creek some metres to the west of that bridge where it turned and proceeded under both bridges in an easterly direction, past the commencement of the dirt track and then swept to the south-east through the dune area behind the south bank of the creek and Park Beach for approximately 500 metres to the harbour. 50 Coffs Harbour had the care, control and management of the land to the west of the Railway Bridge and upon which the walkway commenced. It had been granted a licence from State Rail of a four metre wide strip of land beneath that bridge to enable the construction of the walkway. The land to the east of the Railway Bridge was Crown land known as the Jetty Reserve, the trustee of which was the Coffs Harbour Jetty Foreshore Reserve Trust (the Trust). The land under its care, control and management extended to the southern mean high water mark of the creek. The bed of the creek between the northern mean low water mark and the southern mean high water mark was unalienated Crown land managed by the Marine Park Authority. However, it was accepted that its control did not extend beyond marine and ecological matters as a consequence whereof the State of New South Wales (the State) was accepted as being responsible for that part of the bed of the creek between the mean high and low water marks to which I have referred. 51 I mention these matters because an issue arose as to whether Coffs Harbour had sufficient de facto care, control and/or management of the southern bank of the creek as to impose upon it a relevant duty of care in addition to that imposed upon the State and/or the Trust in respect of their de jure and de facto care, control and management of that part of the creek. 52 Apart from signs attached to the Railway Bridge warning against the dangers associated with the railway, as well as directing people not to trespass upon railway property, there were two signs which had been erected by Coffs Harbour. The first was erected between the two bridges reading: "Coffs Harbour City Council, Coffs Harbour Water. Harbour Co-op 1.2km; Mutton Bird Island 1.8km" The other sign was located adjacent to the walkway at a point where it is moved away from the southern bank of the creek in a south-westerly direction across the dunes. It read: "This Beach is Unpatrolled." 53 Mr Mulligan had seen the first of these signs and those on the Railway Bridge but had not seen the second. This was because, as will appear, Mr Mulligan and his girlfriend had come to the area via the Orlando street end of the walkway diverting at the point where the dirt track joined the walkway to proceed onto the southern bank of the creek. 54 Originally it had been Mr Mulligan's intention to swim at Park Beach rather than in the creek. However, having observed the condition of the surf from the southern bank of the creek, he decided instead to swim in the creek. He and his girlfriend first swam in that part of the creek just to the east of the Railway Bridge. No question arose of Mr Mulligan diving in this part of the creek as he determined that it was too shallow and therefore not safe to do so. Accordingly, the couple moved east along the southern bank of the creek to a point opposite a group of people who were swimming alongside the most eastern of the training walls on the northern side of the creek. 55 After moving his belongings further down the southern bank of the creek, Mr Mulligan entered the water at a spot slightly to the east of the western end of the eastern training wall. Immediately he noticed that the water was a lot deeper than it had been nearer to the Railway Bridge. He took about six or seven steps towards the centre of the creek (in a northerly direction) and found that the creek went from "quite shallow down to his thighs fairly quickly". At a point where the water came up to around the bottom of his swimming trunks he dived forward from a standing position into the creek in roughly an easterly direction, and projected himself under the surface by pulling his hands back by his side as the force of the dive propelled him forward. Upon surfacing he attempted to touch the bottom but could not do so. He noticed that there was a strong seaward current being created by the tide that was running out. He then breast stroked towards the sea allowing the current to carry him along – an experience he found to be "pleasurable". After some distance he exited the water at a point where the creek became shallower as it approached the sea. He then returned to the area where he had left his belongings and repeated the exercise six or seven times over the next half hour. 56 As Mr Mulligan dived forward on each occasion he was not aware of the depth of the water before him. Indeed, as far as he was concerned, he did not know whether the water beyond was " four feet or fourteen feet deep". He did try to ascertain the depth of the water at various points along the creek as he swam towards the sea but on each occasion he was unable to touch bottom until the creek shallowed out as it approached the sea. However, he did notice factors such as the variability of the creek bed, the speed of the current, the fact that the water was cloudy and visibility limited. He agreed that he would have been conscious as he dived each time that because he did not know the depth of the water it was better to make a shallow rather than a deep dive. However, when asked whether he knew that it was dangerous to dive into water of variable depths, he responded in the affirmative but added that he did not know that it was "that variable" as he "only knew it was shallow at the bank and got deeper as I went into the centre". 57 On the fateful dive he once again waded out to roughly the same commencement point and dived forward. However on this occasion he hit his head on the sandy creek bed, breaking his neck. The primary judge found that Mr Mulligan carried out this final dive in the same manner as his earlier, successful, dives in that he did not dive more deeply than he had on the other occasions and had executed what was described as a shallow style of dive. The only difference on this occasion was that he struck an elevated sand dune that formed part of the bed of the creek and which had been formed by the force of the current in the particular tidal flow conditions existing at the time. 58 There was a deal of expert evidence called with respect to the formation of the sand dunes or bedforms in the creek in respect of which the primary judge's findings may be summarised as follows: (a) the phenomenon of sand dunes or variable height bedforms in estuaries and rivers particularly on the eastern seaboard of New South Wales was a well known and natural phenomenon. It was typical of a situation to be found in tidal estuaries around the world; (b) accordingly it was the movements of water along the creek, particularly the tidal movements, which caused the formation of the bedforms of the creek. These bedforms were transient in the sense that as the tide moved in and out the bedforms were in a state of constant flux and change. The sand dunes were bedforms that appear, disappear and reappear in different parts of the creek and ocean bed and are sometimes large and sometimes not, sometimes hard and sometimes soft; (c) ocean, tidal and weather conditions were likely to have resulted in the presence of bedforms on the creek bed at the time of Mr Mulligan's accident. The size of these bedforms would have varied considerably and it was quite likely that there were at least some bedforms, which were reasonably significant in height compared to the water depth. Although it was not possible to be precise about the height of the bedforms it was clear that they would have had more than a minimal impact on the variability of the depth of the creek; (d) in the area where Mr Mulligan was diving, the probability was that these bedforms would have been of a height of less than 0.5 metres. However, the proliferation of bedforms within the relevant part of the creek were within normal and naturally occurring limits appropriate to a tidal estuary of the dimensions of Coffs Creek. 59 The primary judge summarised his factual findings in the following paragraphs of his judgment: "293 …Here, it is true that the plaintiff did not know the depth of the water that lay in front of him when he made his last dive. He was not able to see his feet nor the creek bed below them at the point each time when he dived into the creek. He knew how deep the water was where he was standing and made certain assumptions about the depth beyond that point. He did not know whether the water beyond was "four feet or fourteen feet deep". He also knew in a general sense that the creek was of variable depth. For example, he knew (or believed probably erroneously) that the water in the first area where he swam was not safe to dive. He thought that it was too shallow. He knew in the second area that the water was of variable depth. He had in fact taken a sudden step down to a deeper position before he made his first dive. He knew as well that it was dangerous to dive in water which was of variable depth. At least, he knew this in a generalised way. He agreed with this proposition when it was put to him but said that he did know it was "that variable". He "only knew" that it was shallow at the bank and got deeper as he went into the centre. He agreed however, that although he made an assumption that it was deep enough to dive he in fact did not know one way or another whether it was deep enough to dive. 294. The necessary analysis must be made bearing well in mind that the plaintiff was an experienced swimmer, a strong swimmer and experienced at diving. It is true that he had not swum in a creek before and that Australian conditions were not known to him at the time of his accident. But the existence of sand dunes in tidal conditions are not confined to creeks. They occur in the ocean and they occur in creeks and oceans worldwide. The plaintiff certainly knew that the creek was sand based and that its depth varied at different positions. In other words, he knew two things: first that the water depth was variable. Second, that the variability in part related to the condition of the creek bed. …" 60 The primary judge held ([247], [256], [261]) that Coffs Harbour, the State and the Trust owed to members of the public resorting to either the northern or the southern reserve when swimming in the creek generally in the area between the bridges and the ocean, a "generalised duty of care – to take reasonable steps to avoid foreseeable risk of injury". As in the case of Vairy, the critical issue was the scope of that duty and whether it had been breached. That is not to say that the existence of a duty of care as well as causation and contributory negligence were not in issue, but it is appropriate to deal initially with the issues of scope of duty and breach, as it was with respect to the resolution of those matters that the primary judge in each case differed. In dealing with these issues Whealy J referred to essentially the same authorities as Bell J. Again, the issue upon which their Honours disagreed was related to whether the relevant risk was obvious or hidden. His Honour referred to the "diving cases" (to which I shall return) in some of which the plaintiff was successful upon the basis that there were found to be hidden dangers that resulted in serious risks emerging for a person diving in a manner that would otherwise be relatively safe. According to the primary judge, Nagle was such a case. 61 It was submitted on behalf of Mr Mulligan that the risk of his striking his head upon the bedform in the creek was hidden because it was neither apparent nor obvious to him that the bedforms would be of variable height due to the natural processes of the movement of the tide. His Honour rejected this analysis on two bases. The first was that in a situation where it is impossible to see into the water because of natural conditions in a creek or, for that matter, in the ocean, by definition everything below the surface of the water is hidden. But to an experienced swimmer such as Mr Mulligan that was an obvious fact that imposed an inherent risk every time such a swimmer dived into turbulent or cloudy water of unknown depth. The second was that what was hidden in this case was a naturally occurring and dissipating sand dune of normal dimensions. 62 The primary judge then defined the relevant risk as "the risk of injury from striking a sand bank or sand dune in the creek bed" and held, as a matter of fact, that risk was obvious and was obvious to Mr Mulligan. Although a remote risk, it would nevertheless have been obvious to an experienced swimmer that a misjudged dive might bring him or her into collision with an uneven sand formation on the creek bed. Swimming in a tidal creek (especially close to the ocean as in the present case) carried with it a risk or danger of injury that, according to his Honour, was inherent in the nature of the activity. 63 The primary judge thus expressed himself in these terms ([299]): "To an experienced swimmer and diver such as the plaintiff, notwithstanding that he was not familiar with Australian conditions and probably knowing nothing of the physics of creek beds, the risk of striking a transient sand dune occurring naturally on the bed of a tidal creek was, as a matter of factual evaluation, an inherent risk involved in swimming and diving in such an estuary. The plaintiff knew in general terms of the danger of diving in a creek of variable depth. …the danger which eventuated fell within the ambit of the normal dangers that, for experienced swimmers, attached to the ordinary activity of swimming in the ocean or in tidal creeks." 64 The primary judge then stated what he regarded as the fundamental difference in the breach analysis between the diving cases where the plaintiffs have succeeded and the present case: "303 … The matter requiring a warning, according to the plaintiff's case related to the presence of variable depth due to the formation of naturally occurring sand dunes in the creek bed. This was a naturally occurring phenomenon in the truest sense of the word. It was part of the natural condition of the creek and indeed of tidal estuaries throughout the world. Ordinary competent swimmers know and can immediately sense that there is variability in creek beds because of the presence of sand dunes underneath their feet as they enter the creek waters. They will know that variability is not uniform because of the varying nature of the sand dunes. They may not understand the physics but they know there is variability. …" 65 Having noted that Mr Mulligan was best placed (and better placed than the defendants) to know about the circumstances and conditions of the creek at the time and place he chose to dive, it was a relevant consideration to ascertaining the response of the reasonable person owing a duty of care to take cognisance of that fact, a corollary of which was that it would be reasonable to assume that Mr Mulligan would use reasonable care for his own safety in making the decisions he did. 66 Accordingly, notwithstanding that the primary judge found that it would have been a relatively cheap and simple measure to put up a sign or signs warning of the variable depth of the creek, the present was a case where the relevantly foreseeable risk was obvious as a consequence whereof there was no breach by Coffs Harbour, the State or the Trust of the duty of care owed by each to Mr Mulligan. Review of the authorities 67 The starting point of this discussion, as it was with the primary judges, is the decision of the High Court in Nagle. There the defendant was under a duty to manage and control for the benefit of the public the reserve known as Rottnest Island. The reserve adjoined a swimming area known as "the Basin" although it was not actually part of the reserve. The plaintiff who had never previously visited the reserve or swum at the Basin dived from a partially submerged rock ledge into the water, striking his head upon a submerged rock, thereby becoming quadriplegic. He sued the Rottenest Island Authority claiming that it was negligent in failing to give any or any adequate warning that the ledge was unsafe for diving. According to the finding of facts made by the trial judge, the Authority ran Rottnest Island as a business, deriving revenue from visitors. It promoted the Basin for swimming and related recreational activities by means of publicity and directional signs. It encouraged members of the public to use the Basin as a venue for such activities by installing and maintaining appropriate facilities. 68 The majority (Mason CJ, Deane, Dawson and Gaudron JJ) held (at 430) that the Authority was under general duty of care at common law to take reasonable care to avoid foreseeable risks of injury to visitors lawfully visiting the reserve. The basis for that holding was that the Authority, by encouraging the public to swim in the Basin, brought itself under a duty of care to those members of the public who swam in that location. By encouraging persons to engage in that activity, the Authority came under a duty to take reasonable care to avoid injury to them and "the discharge of that duty would naturally require that they be warned of foreseeable risks of injury associated with the activity so encouraged". 69 When it came to the possibility that a person might dive into the water in circumstances where it was not safe to do so, their Honours said (at 431): "It is now well established that a person who owes a duty of care to others must take account of the possibility that one or more of the persons to whom the duty is owed might fail to take proper for his or her own safety". As will appear later in these reasons, the High Court has, in my opinion, somewhat modified this statement as well as the rule of the case and its ratio decidendi in accordance with the process described by McHugh J in Woolcock Street Investments Pty Limited v CDG Pty Limited (2004) 78 ALJR 627 . 70 As I have noted, their Honours had held that the discharge of the Authority's duty would naturally require that those who had encouraged swimming activities in the Basin should be warned of foreseeable risks of injury associated therewith. Having held that the risk of injury was foreseeable, their Honours turned to the question of breach. So far that issue had not been determined by the passage that I have cited above. Having commented upon the form which any relevant warning might take, it would appear that their Honours found (at 432) that the failure to warn of the danger of diving from the rock ledge into the Basin due to the presence of rocks was a breach of the Authority's general duty of care upon the basis that, firstly, there were appropriate warning signs that could have been erected, secondly, the Authority had the power to erect signs at the probably point from which the plaintiff had dived and, thirdly, there was no reason why the Authority could not erect signs on the platform warning of the danger which existed notwithstanding that the Basin into which the plaintiff dived was beyond the boundaries of the reserve. 71 Several observations can be made with respect to their Honours' reasoning. The first is that although reference was made to the finding of the trial judge that when the appellant dived into the water of the Basin, his visibility may have been affected by a sun glint or glitter pattern as a consequence of the reflection of sunlight on the water thus obscuring his vision to some extent (although the rock which his head struck would not have been totally obscured), no question of the obviousness of the risk of injury from diving into partially obscured water played any part in their Honours' consideration of breach of duty. Secondly, their Honours appeared to have approached the issue of breach upon the basis that if the risk of injury associated with diving into the Basin was foreseeable, then the only way that that duty could be discharged would be by the Authority warning of that risk. In other words, provided there was no impediment, legal or practical, to the erection of a warning sign, the Authority would be in breach of its duty if it failed to erect such a sign warning of the foreseeable risk of injury. Thirdly, it is noteworthy that although their Honours made reference to Shirt when dealing with the issue of foreseeability, no reference was made to the Shirt calculus or any attempt made to apply its elements to the facts of the case when their Honours consider the issue of breach of duty. 72 The second and third points of the foregoing observation should be considered immediately lest it be assumed that, after Nagle, Shirt was authority for the proposition that there is a breach of duty if the risk of injury is reasonably foreseeable and removal of that risk by the adoption of simple and cheap measures (such as a warning sign) is practicable but not undertaken. As Heydon JA, with whom Meagher JA and Foster AJA agreed, noted in Van Der Sluice v Display Craft Pty Ltd [2002] NSWCA 204 at [83], such a reading of Shirt would be fallacious as the proposition that the suggested measures "would have been a cheap and practical response to the foreseeable risk begs the question of whether it was necessary for the defendant to embark on that response…Mason J [in Shirt ] left open as the response of a reasonable person the course of doing nothing instead of adopting the simple and cheap measures." 73 A similar point was made by Hayne J in Brodie v Singleton Shire Council (2001) 206 CLR 512, 631 where his Honour observed ([318]): "As I have said, however, the search for some unifying principle or principles which will explain why an analogy has been drawn with previous authority in some cases but not others has so far proved unsuccessful. All that emerges is that foresight of harm, and capacity to avoid it, has been said not to be enough. 'Something more' must be found. If, however, the expansion of duty of care continues on its current path, foresight of harm and capacity to avoid it will become the only criteria which underpin the imposition of a duty of care. In that event, duty of care would serve no purpose in identifying the cases in which liability is to be found. The only questions would be whether a defendant in fact acted without reasonable care, or failed to act when it would be reasonable to do so, and whether that act or omission was a cause of the plaintiff's loss or damage." 74 I return to my review of the authorities. Nagle was decided on 21 April 1993. In Public Trustee as Administrator of the Estate of the later Peter Saroukas v Sutherland Shire Council (1992) Aust Torts Report 81-149, decided a little over a year earlier, the defendant council had the care, control and management of a park beside a bay which was extensively used by the public. At the edge of the park were tidal baths that were separated from the bay by a walkway that had been constructed by the council around the baths. Around the outside of the walkway was a rail fence but it was possible to climb through or over it. The defendant erected numerous and prominent signs that warned of the danger of diving into the baths and of the variable depth of the water in them but had not erected any sign warning of the risk of diving from the walkway into the bay. In this respect the depth of the water in the bay also varied and the surface was such that it was very difficult, and frequently impossible, to visually assess its depth. Whilst walking along the walkway between the baths and the bay with no intention of swimming or diving, one of the plaintiff's shoes fell into the bay whereupon he climbed through the fence and dived into the water. The water was only three feet deep and he ended up a quadriplegic. 75 Gleeson CJ, with whom Priestley and Handley JJA agreed, held firstly, that the defendant owed the plaintiff a duty of care which extended to persons diving from the walkway into the bay and, secondly, that it was in breach of that duty in that part of the facilities it had provided for the public included the walkway which was intended for public use for recreational purposes. As the risk that a person might dive into the bay from the walkway and suffer injury as a consequence was foreseeable, the defendant failed to discharge its duty of care by failing to erect an appropriate pictorial sign warning of the danger of diving from the walkway into the bay. 76 For present purposes the critical part of the Chief Justice's judgment is as follows (at 61, 138 (citations omitted)): "Whilst it is true to say that the Council did not intend that people should dive from the walkway into the Bay outside the baths, nevertheless the Council provided a recreational facility which made that possible, and the risk that a person might dive out into Gunnamatta Bay from the walkway and suffer injury as a consequence was foreseeable...the necessary relationship and proximity between the respondent and the deceased existed, and the learned trial judge was correct in concluding that the respondent was under a duty to warn those using the walkway of the dangers of diving into variable depth tidal waters. It was submitted on behalf of the respondent that the circumstances of the deceased dived from one side of the walkway rather than the other meant that there was no duty upon the respondent to warn the deceased of the risk involved. As an absolute proposition this cannot be correct. Suppose, for example, that to the knowledge of the Council the bed of Gunnamatta Bay immediately outside the swimming pool was covered with large quantities of broken glass. It cannot be the case that there would be no duty upon the Council to warn users of the walkway of that danger. The very existence of the Council's walkway going out into the bay creates the possibility that people would or dive from it. Once it is accepted as a possibility that the Council's recreational facility be used in that way then it would be taking far too narrow an approach to limit the Council's obligation to an obligation to give a warning to people who intend to jump or dive in one direction rather than another." 77 The Chief Justice did not deal expressly with the question of breach. However, he did hold (at 61, 139) that as there was a possibility that somebody might decide to jump from the walkway into the bay rather than the baths, the attendant risk of such an activity was not something that the defendant was entitled to disregard. However, like the majority in Nagle, his Honour did not in terms apply the Shirt calculus except with respect to the issue of foreseeability; nor did any question of the obviousness of the risk of jumping or diving into variable depth tidal waters arise for consideration. Furthermore, the walkway from which the plaintiff dived was an artificial structure created by the defendant for recreational purposes and which provided the clear opportunity, if not the temptation, for persons to dive from it into the bay. As a creation of the defendant the walkway, in my opinion, falls into a different category to cases such as the present where no such artificially created situation is involved. This is a point picked up by Hayne J in Romeo at 489 ([157]) to which I later refer. 78 Inverell Municipal Council v Pennington (1993) 82 LGERA 268 was decided by this Court three months after Nagle. Like Saroukas it involved the creation by the defendant council of an artificial structure, namely, a municipal swimming pool. The plaintiff dived into the pool from a point where the water was insufficiently deep given his size and weight, as a consequence whereof he struck his head on the bottom and became a quadriplegic. The only depth notices were on each side at the deep end of the pool showing 11'6" and one at each side of the 6' mark. The trial judge held that the defendant was liable in negligence, a decision upheld by this Court. 79 It was found that the plaintiff was aware of the dangers of diving into water that was too shallow. He thought he was diving into water that was no more than 5' deep. He was aware that the depth of the pool varied from one end to the other. He therefore knew that he was diving into water that was less than his height and therefore, objectively considered, posed a risk of injury to him. 80 Mahoney JA found that the relevant default on the part of the defendant was that it did not bring the danger and the depth to the plaintiff's immediate attention so that the absence of signs warning of the danger of diving and the absence of depth indicators resulted in the plaintiff not being warned and made subjectively aware of the danger he was taking. 81 Having stated the Shirt calculus, his Honour noted (at 272) that it was "believed by some that once a risk of injury was relevantly foreseeable and if that risk was not far-fetched or remote that it could properly be put aside, then there was a duty upon the defendant to remove or neutralise that risk. That could be done either by removing the factual circumstances which gave rise to the risk or, in some cases, by bringing the risk sufficiently to the plaintiff's attention that the risk of injury was effectively excluded." 82 His Honour then expressed the view that the judgment of Mason J in Shirt established that the law did not in every case require a defendant to go so far. He continued (at 272): "It [the Shirt calculus] measures what the defendant is to do by the response of the reasonable person. That response is to be measured by, inter alia, the consideration to which his Honour has referred, namely, the magnitude of the risk, the probability of its occurrence, the seriousness of the injury, what is necessary to guard against it, and the resources available for the defendant to provide against it. The principle envisages, in my opinion, that in some cases a reasonable person would accept the continuance of a risk that was not far-fetched or remote and the law would not hold him responsible if he did." 83 His Honour noted the argument of the defendant that a plaintiff is required to exercise appropriate care for his own safety and that what a reasonable person would do is to be determined upon the basis that a person diving into a pool will at least satisfy himself that the water is sufficiently deep. Although not expressed in terms of obviousness of the risk of danger of diving into a pool of unknown depth, the defendant's argument had overtones of such a proposition. Mahoney JA's response thereto was as follows (at 273): "I do not dissent from this view, as a general principle. In the end, the court must determine what is the response appropriate to the whole of the circumstances of the case. But a person who crosses the street must do so with his eyes open. A motorist on the street must be conscious that pedestrians may act without care or foolishly, but special cases apart, he is not required to take the care appropriate to the risk that the pedestrian has simply closed his eyes." 84 One might paraphrase and adopt his Honour's language to the present case by asserting that a public authority is not required to take the care appropriate to the risk of injury from diving into water of unknown depth where the diver has simply closed his or her eyes to the obvious. 85 Having observed that the burdens which the law of negligence poses are, in the view of some, inappropriately heavy, his Honour considered (somewhat reluctantly I think) that, in the light of the decision in Nagle which illustrated the standard of care required, the trial judge had not erred in holding that, in failing to bring to the attention of the plaintiff the dangers created by diving into a pool of the kind in question, the defendant council had not discharged the duty placed upon it because, having set up the pool facility, it had in the relevant sense created the danger which caused the plaintiff's injury. 86 Clarke JA considered that the appeal failed whilst the law remained as expressed in Nagle. His Honour then questioned whether that decision had effectively placed the council in the position of an insurer. He opined (at 275) that this resulted in a consideration of the reasonableness of conduct and the reaction of the reasonable person being replaced by a mechanical test, which in a real sense looked only to the means available to guard against a risk of injury, no matter how unlikely it is that that injury will occur. He then proceeded with a discourse upon the development of the law in this area. In the course of doing so, he referred to what Gibbs CJ said in Turner v South Australia (1982) 56 ALJR 839, 840: "Where it is possible to guard against a foreseeable risk which, although perhaps not great, nevertheless cannot be called remote or fanciful by adopting the means which involves little difficulty or expense, the failure to adopt such means will in general be negligent" 87 It is to be noted that this passage from Turner was made in the context of the duty of care owed by an employer to an employee. On the other hand the Chief Justice, although not referring expressly to the Shirt calculus, did adopt that part of its language describing a foreseeable risk. But that is only the gateway to the exercise for which Shirt is authority: see [60] above. 88 According to Clarke JA, it was this approach that was adopted in Nagle notwithstanding the likelihood that someone would dive into rocks that were visible to him must have been very small indeed. He thus posed the question (at 279): "Should we not accord much greater weight to the possibility, bearing in mind the enormous range of foreseeable risks involved in virtually every form of activity, that the reasonable person would have struck a balance and decided that a particular risk was remote and that no action was called for despite the fact that it may cost little to provide a measure of protection?" 89 Meagher JA agreed but, again, his Honour considered that the result was dictated by the decisions of the High Court in Shirt and Nagle. He said (at 283): "It is indeed a surprising result, but it is one an intermediate appellate court cannot remedy. It is a result which is mandated on us by the two High Court decisions [ Shirt and Nagle ] to which I have referred. So long as a duty arises, whenever the occurrence of the risk is not fanciful, a duty will arise in every single case. It does not follow that the defendant will be liable in every single case, but it does follow that he will be unless it can be proved that to avoid the risk will be wholly unreasonable." 90 The misgivings of both Clarke and Meagher JJA in Pennington were, though not consciously, responded to by the High Court in Romeo, which although declining to overrule Nagle, modified its impact and apparent absoluteness. 91 In Romeo the defendant Commission managed a nature reserve, which contained a car park at the top of a cliff. The plaintiff, at night and whilst intoxicated, fell from the top of the cliff onto a beach below and sustained serious injuries. There was no barrier at the edge of the cliff and its presence was obvious. It was held by the whole court that the defendant was under a duty to persons entering the reserve to take reasonable care to avoid reasonably foreseeable risks of injury – people falling off the edge of the cliff was one of those risks. However, the majority held that the defendant was not in breach of that duty by failing to erect a fence or other barrier at the edge of the cliff. In the light of Nagle, all members of the court held that the Commission was under a duty of care whilst that decision stood. So far as the issue of breach of duty was concerned, Toohey and Gummow JJ, after referring to passages from the joint judgment in Nagle at 431, and in particular the passage I have cited in [69] above, observed (at 454 [50]): "But this does not mean that the respondent was obliged to ensure, by whatever means, that those coming onto the Reserve would not suffer injury by ignoring an obvious danger. This is particularly so in the case of the cliff which did present an obvious danger" 92 Accordingly, their Honours considered that notwithstanding that there was a "risk" of someone falling over the edge of the cliff in the sense that such a risk was not far-fetched or fanciful but was real and therefore foreseeable, nonetheless that risk existed only in the case of someone ignoring the obvious. It followed that the Commission was not required to take steps in order to discharge its duty of care by guarding against what was obvious namely, the risk of falling over a cliff the presence of which was obvious. This finding is to be contrasted with that of this Court in Ah Tong v Wingecarribbee Council [2003] NSWCA 381 where the existence of a cliff created by a concealed, disused quarry was held not to be obvious: see per Ipp JA at [63] and [64]. 93 Kirby J discussed the scope of the duty of care in these terms (at 478 [123]): "The ordinary formulation of a common law is that bodies such as the Commission must take reasonable care to avoid foreseeable risks of injury to persons entering an area such as the reserve, including the cliffs, as of common right. However, that expression of the duty must be elaborated if it is to be of any practical guidance. The entrant is only entitled to expect the measure of care appropriate to the nature of the land or premises entered and to the relationship which exists between the entrant and the occupier. The measure of the care required will take into account the different ages, capacities, sobriety and advertence of the entrants. While account must be taken of the possibility of inadvertence or negligent conduct on the part of entrants, the occupier is generally entitled to assume that most entrants will take reasonable care for their own safety…But where, as here, the statutory duties are stated in general and permissive terms, the scope of the duty of care imposed by the common law will be no more than that of reasonable care . Where a risk is obvious to a person exercising reasonable care for his or her own safety, the notion that the occupier must warn the entrant about that risk is neither reasonable nor just ." (emphasis added) 94 His Honour then sought to distinguish Nagle on the following basis (at 481 [131]): "The important distinction between this case and Nagle is that there the danger of the submerged rocks was hidden from the ordinary users of the Basin. Here, the danger of the elevation of the cliffs was perfectly obvious to any reasonable person." 95 The distinction referred to by his Honour is of some poignancy given that the suggestion that the submerged rocks upon which Mr Nagle foundered were hidden did not seem to play a part in the majority decision that the Authority had breached its duty of care. It was referred to by the majority in Nagle (at 427-428) only in the context of a recitation of the "Background". Further reference was to the finding of the trial Judge that notwithstanding the reflection of the sun on the water, the rock upon which the plaintiff struck his head would not have been totally obscured and the glare could have been avoided by moving his head. It would seem that this finding of the trial judge fell short of one that the rock was a hidden danger, but even if it was, that fact was ignored in the majority's reasoning. Nevertheless, it is difficult to see how the results in Nagle and Romeo can be reconciled unless the distinction is between a hidden danger in the one case and an obvious danger in the other. 96 Hayne J referred to the relevance of whether the danger has been created by the action of the public authority or is one occurring naturally in the following passage (at 488-489): "157. What is reasonable must be judged in the light of all the circumstances. Usually the gravity of the injury that might be sustained, the likelihood of such an injury occurring and the difficulty and cost of averting the danger will loom large in that consideration. But it is not only those factors that may bear upon the question. In the case of a public authority which manages public lands, it may or may not be able to control entry on the land in the same way that a private owner may; it may have responsibility for an area of wilderness far removed from the nearest town or village or an area of carefully manicured park in the middle of a capital city; it may positively encourage or at least know of, use of the land only by the fit and adventurous or by those of all ages and conditions. All of these matters may bear upon what the reasonable response of the authority may be to the fact that injury is reasonably foreseeable. Similarly, it may be necessary, in a particular case, to consider whether the danger was hidden or obvious, or to consider whether it could be avoided by the exercise of the degree of care ordinarily exercised by a member of the public, or to consider whether the danger is one created by the action of the authority or is naturally occurring, but all of these matters (and I am not be taken as giving some exhaustive list) are no more than particular factors which may go towards judging what reasonable care on the part of a particular defendant required. In the end, that question, what is reasonable, is a question of fact to be judged in all the circumstances of the case." 97 It is pertinent to note that whether the danger was hidden or obvious was, in effect, regarded by his Honour as only one of a number of considerations required by the Shirt calculus to be taken into account in determining if there had been a breach of a duty of care. 98 Although not a diving case, Romeo was applied by the Victorian Court of Appeal in Secretary to the Department of Natural Resources & Energy v Harper [2000] 1 VR 133. In that case, the plaintiff was injured whilst visiting a national park: a falling tree struck her in gusty winds. It was held by Tadgell and Batt JJA that there was no breach by the defendant of its duty of care by failing to erect an appropriate sign or signs warning of the danger of hazardous trees in the reserve in certain weather conditions as that danger was an obvious one (at any rate in high winds) and was endemic in the outdoor recreational activities undertaken in such reserves. 99 Batt JA said (at 148 [47]): "There are two principal reasons why, in my view, the taking of reasonable care did not require the taking by the appellant of any such precaution to guard against an accident of the kind that occurred to the respondent. First, the danger to be guarded against, that of death of injury from falling trees or limbs, was an obvious one, at any rate in high winds. The appellant was entitled to expect adult residents of Victoria, such as the respondent, to know that trees and limbs of trees in forests, reserves, parks and other places occasionally fall, at any rate in high winds, and do so randomly." 100 After referring to "the common course of human experience", his Honour continued: "To enter a forest or its immediate surrounds, like entering the surf, is to take a risk of injury, albeit a remote risk. The risk is 'endemic' or part and parcel of the recreation of camping, walking and indeed living outdoors in the Australian bush and in particular in forest reserves…the position might be different if the tree in question had been hazardous in the sense in which I have used that word, as it might also be at a beach where the surf was frequently subject to treacherous currents not obvious to a stranger to the beach. The question is one of fact and accordingly is not governed by other cases." 101 The above passages in Harper were relied upon by Ipp J, with whom Wallwark and Parker JJ agreed, in Prast v Town of Cottesloe (2000) 22 WAR 474. In that case, the appellant, who had been bodysurfing many times before, was dumped by a wave while bodysurfing at Cottesloe Beach, which was managed by the respondent. He was thrown onto his head on the ocean bed and as a result became a tetraplegic. The appellant claimed that the respondent was in breach of its duty of care by failing to erect signs warning of the risk of serious spinal injury by reason of the condition of the surf. 102 Ipp J applied Nagle in holding that the respondent owed a duty to take reasonable steps to avoid foreseeable risk of injury to the appellant but applied Romeo in holding that there was no breach of that duty by reason of the fact that the risks of being dumped by surf and thereby sustaining bodily injury, were endemic to and part and parcel of the recreation of bodysurfing and that those risks were obvious and should have been known to the appellant. 103 His Honour (at 481 [29]) noted that the issue of breach of duty raised questions of both fact and law. The factual question was the extent to which the risk of serious injury from bodysurfing was obvious. The legal question concerned the effect of the obviousness of the risk and the obligation to take reasonable steps to avoid foreseeable risk of injury. The trial judge had answered the factual question by holding that there was no hidden danger and that the danger of being dumped was obviously inherent in bodysurfing. He had distinguished the present case from the "diving" cases such as Nagle and Pennington on the basis that the plaintiffs in those cases were injured, in effect, by the materialisation of a risk of which they were not aware, whereas in the instant case the appellant's injury was brought about by an obvious risk inherent in bodysurfing. 104 Ipp J agreed that the trial judge was correct in distinguishing between the circumstances of the diving cases and those of the present case. At 482 [32] his Honour observed: "In the diving cases there were hidden dangers that caused there to be serious risks in performing an act which would otherwise be relatively safe. The risks of striking one's head on submerged rock obscured by the glare of the sun, or on a misleadingly shallow bottom, are not an inherent part of diving. Those were hidden dangers that brought about the need to warn. They are to be contrasted with the risk facing all bodysurfers i.e., the risk of being hurled on to the seabed, out of control, by a wave that turns out to be a dumper. The risk of so being dumped is inherent in body-surfing itself, cannot be avoided and is well-known." 105 It is to be noted that his Honour regarded the submerged rock in Nagle as a hidden danger due to it being obscured by the glare of the sun. Of equal relevance to the present case is his Honour's suggestion that "a misleadingly shallow bottom" is also a hidden rather than an obvious danger. Given his Honour's previous reference (at 481 [30]) to Pennington and to City of Rockingham v Curley (to which I shall return), it might be said that he was confining that remark to misleadingly shallow swimming pools or other artificial structures created by the defendant rather than, as in the present cases, to water which was of deceptively shallow depth due to the natural movement of sand caused by the ebb and flow of the tide or littoral drift. 106 As to the relationship between the obviousness of the risk and the discharge of the duty of care, his Honour, after citing from Romeo and Harper, concluded (at 485 [44]) that: "a local authority charged with maintaining safety at a popular metropolitan beach is not required, in the discharge of the duty of care it owes to those who come to swim on the beach, to warn about the risks of bodysurfing. Negligence at common law is still a fault-based system: see Perre v Apand Pty Limited (1999) 198 CLR 180 at 230 per McHugh J. As a matter of law, there is a point at which those who indulge in pleasurable but risky past-times must take personal responsibility for what they do. That point is reached when the risks are so well-known and obvious that it can reasonably be assumed that the individuals concerned will take reasonable care for their own safety: see Romeo v Conservation Commission (NT). " 107 The decision in Prast can be contrasted with that of the Full Court of the Supreme Court of Western Australia in City of Rockingham v Curley (2000) 112 LGERA 123 decided approximately six weeks before Prast. It involved a young man who dived into shallow water from a jetty and suffered serious injuries. Wallwark and Murray JJ held that the public authority in which the jetty was vested breached its duty of care by failing to take steps to prevent a foreseeable risk of injury by prohibiting diving and by erecting appropriate signs. The Commissioner who heard the action found that at the location from which the plaintiff dived, it could not have been obvious to a person exercising reasonable care that a dive could not be performed safely. He also found that it had not been obvious to certain witnesses that it was unsafe to jump or dive from the point on the jetty where the plaintiff had dived. 108 On appeal, it was submitted by the appellant that a dive by a person such as the plaintiff, from a height above the water surface of 8 feet into a depth of 4 foot of water was suicidal. It was further contended that it was inherently and obviously dangerous to dive from a jetty which was 2.5 metres above the water without first checking the depth of the water. 109 Wallwark J considered that it was important that the plaintiff had dived at the particular location many times before without a problem. This notwithstanding, the appellant had submitted that its duty of care did not extend to expressly warning users of the jetty not to dive into the water at the point at which the plaintiff did so, there being an inherent obligation or expectation that people would take reasonable care for their own safety. As recorded by his Honour (at 135 [80]) it was submitted "(t)hat there was no obligation to warn of the blindingly obvious, just as there is no need to put signs on highways saying 'it is dangerous to cross this highway' " 110 Wallwark J rejected these submissions upon the basis that they were contrary to the findings of the Commissioner. It will be recalled that that finding was that it would not have been obvious to a person exercising reasonable care that a dive at the location from which the plaintiff dived could not be performed safely. 111 I would interpolate that in my respectful opinion, the Commissioner had asked himself the wrong question. It was not a question of whether it was not obvious to a person exercising reasonable care that a dive could not be performed safely but, on the contrary, whether it was obvious to such a person either that the dive could be performed safely or, perhaps more appropriately, that it could not be performed safely without first checking the depth of the water at the time of the dive. This is particularly so where the depth of the water is known to be variable due to natural phenomenon such as movements of the tides. 112 Murray J at 146 [47] noted that in Romeo the question of whether the scope of the duty of care included taking reasonable measures to guard against an obvious danger was considered by Toohey and Gummow JJ to be an aspect of breach of the duty. He held that in the present case the breach arose because of the finding of the Commissioner that at the point from where the plaintiff dived, it was no longer obvious to a person exercising reasonable care that a dive could not be performed safely. 113 Anderson J dissented. His Honour referred (at 153 [183]) to the finding of the Commissioner that it was not obvious that a dive could not be performed safely at the location from which the plaintiff dived suggesting that he intended to say that it was not obvious to the eye that the water was dangerously shallow beneath the dive point. 114 However, his Honour was of the view that there was no proper basis upon which the plaintiff could make any assumption as to the depth of the water or that it was sufficiently deep to enable him to dive safely. At 155 he expressed his conclusion in these terms: "188. In my opinion, it is clear that the plaintiff knew what anyway is notorious – that it is dangerous to dive into shallow water. It is clear that he could see the bottom and did see the bottom. He must have appreciated, if he had given it any thought at all, that the water at this location on this day was dangerously shallow for a head-first dive from the deck of the jetty at the point from which he dived. 189. There was no hidden sandbar or submerged pylon or a reef hidden from view, or anything of the kind. There was no specific finding that by reason of some optical illusion the water may have appeared to have been deeper than it was." 115 As his Honour points out (at 155 [190]), the optical illusion when one looks into water is explained by the laws of physics by reference to the refraction of light. Because light bends when it enters a medium of different optical density such as water, objects appear closer to the surface than they are. Thus the optical illusion brings the bottom closer and makes it appear shallower than it is. However his Honour did not, it seems to me, consider whether the appearance or the perception of the depth of water being shallower than it in fact is (by reason of the optical illusion to which I have referred) rendered the danger of diving into water of unknown depth a hidden rather than an obvious danger. 116 His Honour then observed (at 156): "196. In my opinion, the conclusion ought to have been that the danger of striking the bottom should a dive be made from the point at which the plaintiff made the dive was obvious to the plaintiff. He required no warning signs to alert him of it. There should have been a finding that no person exercising reasonable care for his or her safety would have executed the dive by which the plaintiff was injured." 117 After citing from the judgment of Kirby J in Romeo (at 478 [123]), his Honour concluded in the following terms (at 158 [206]): "Swimming and diving in the sea and rivers are most enjoyable and an important recreational past-time in this State and the long history of the use of the structure for those purposes is devoid of any similar incident to that suffered by the plaintiff. There are many sections of this structure [the jetty] from which it is perfectly safe to dive if reasonable care is used. There are many, many jetties and landing stages and groynes along the Western Australian coastline and the banks of our rivers…Obviously all of these jetties and groynes start on land and reach out across shallow waters to deeper waters, where it may or may not be safe to dive. The depth of water is affected by the natural ebb and flow of tides. It is a matter of simple observation in the experience of living in the community that to a large number of these structures, the public has unrestricted access. I cannot subscribe to the view that there is a common law duty upon every municipality or public authority who has a jetty or groyne under its management or control to put up signs prohibiting diving because someone may ignore the obvious risk of diving head first into shallow water." 118 In my opinion, these observations of his Honour are as applicable to the coast of New South Wales as he considered them to be to the coast of Western Australia. I respectfully agree with them and would only add at the end of the last sentence the words "or water of unknown depth". 119 Before leaving the diving cases and dealing with other authorities in which the obviousness of the risk has been emphasised as highly relevant to the issue of breach, I return to the recent decision of the House of Lords in Tomlinson. It must, of course, be remembered that in England the law with respect to an occupier's duty of care has been codified. Nevertheless, the differences between the relevant statutory provisions and the common law do not, in the present context, justify ignoring the basis upon which their Lordships in that case considered that there was no relevant breach of the respondent's statutory duty of care. 120 Lord Hoffman dealt with the question of whether people should accept responsibility for the risks they choose to run, noting that there was obviously some degree of risk in activities such as swimming and diving. In this context his Lordship said (at 84): "45. I think it will be extremely rare for an occupier of land to be under a duty to prevent people from taking risks which are inherent in the activities they freely choose to undertake upon the land. If people want to climb mountains, go hang-gliding or swim or dive in ponds or lakes that is their affair. Of course the landowner may for his owner reasons wish to prohibit such activities. …he is entitled to impose such conditions, as the Council did by prohibiting swimming. But the law does not require him to do so. 46. My Lords, as will be clear from which I have just said, I think there is an important question of freedom at stake. It is unjust that the harmless recreation of responsible parents and children with buckets and spades on the beaches should be prohibited in order to comply with what is thought to be a legal duty to safeguard irresponsible visitors against dangers which are perfectly obvious. The fact that such people take no notice of warnings cannot create a duty to take other steps to protect them…A duty to protect against obvious risks or self-inflicted harm exists only in cases in which there is no genuine and informed choice." 121 His Lordship concluded (at 85 [48]) that the appeal "gives your Lordships the opportunity to say clearly that local authorities and other occupiers of land are ordinarily under no duty to incur such social and financial costs to protect a minority (or even a majority) against obvious dangers." 122 His Lordship held (at 86 [50]) that even if swimming had not been prohibited and the council had owed a relevant duty under the statute, that duty would not have required it to take any steps to prevent Mr Tomlinson from diving or warning him against dangers which were "perfectly obvious". 123 Lord Hutton agreed with Lord Hoffman but added some comments of his own. His Lordship was of the view (at 89 [59]) that it was contrary to common sense, and therefore not sound law, to expect an occupier to provide protection against an obvious danger on his land arising from a natural feature such as a lake or a cliff or to impose a duty on him to do so. His Lordship then cited (at 89 [61]) a statement of Henry LJ in Whyte v Redland Aggregates Ltd (unreported) 27 November, 1997; Court of Appeal (Civil Division), a case where the plaintiff dived into a disused gravel pit and alleged that he had struck his head on an obstruction on the floor of the pit. The Court of Appeal dismissed his appeal against the rejection by the trial judge of his claim for damages. In the course of his judgment Henry LJ made the following observation (omitting citations) which, in my respectful opinion, is particularly apposite to the present cases: "In my judgment, the occupier of land containing or bordered by the river, the seashore, the pond or the gravel pit, does not have to warn of uneven surfaces below the water. Such surfaces are by their nature quite likely to be uneven. Diving when you cannot see the bottom clearly enough to know that it is safe to dive is dangerous unless you have made sure, by reconnaissance or otherwise, that the diving is safe, i.e. that there is adequate depth at the place where you choose to dive. In those circumstances, the dangers of there being uneven surface in an area where you cannot plainly see the bottom are too plain to require a specific warning and, accordingly, there is no such duty to warn. There was no trap here on the judge's finding. There was just an uneven surface, as one would expect to find in a disused gravel pit." 124 A little later (at 90 [63]), his Lordship referred to what May LJ had observed in Darby v The National Trust [2001] PIQR 372 at 378: "It cannot be the duty of the owner of every stretch of coastline to have notices warning of the dangers of swimming in the sea. If it were so, the coast would have to be littered with notices in places other than those where there are known to be special dangers which are not obvious." 125 It is important to observe that Lord Hutton (at 91 [65]) noted that there might be exceptional cases where a claimant might be able to establish that the risk arising from some natural feature on the land was such that the occupier might reasonably be expected to offer him some protection against it. He exemplified a very narrow and slippery path with a camber beside the edge of a cliff from which a number of persons had fallen. 126 Finally, Lord Scott (at 99 [93]) observed that a dive which involved a hands-arms-head-first movement from a standpoint above the water down into the water was "dangerous if the depth of the water is unknown for the obvious reason that if the depth is inadequate the head may strike the bottom of the pool or the lake before the diver is able to check his downwards trajectory and curve out of the dive". The foregoing observation applies in turn to Mr Vairy, and for reasons which will become apparent, I consider it also applies to Mr Mulligan. 127 A similar conclusion was reached by Morland J in Rhind v Ashbury Water Park Limited & Anor [2003] EWHC 1029 (QB), a case decided two months before Tomlinson in the House of Lords. After noting Whyte, Derby and Tomlinson (in the Court of Appeal), his Lordship observed (at [55]) with respect to a plaintiff who sustained incomplete tetraplegia, when he dived into a body of water: "The risk of injury through diving because of the dangers of diving into too shallow water and striking one's head on the bottom or on an obstruction on the bottom is so obvious that in my judgment those defendants owed no duty to post specific warning of that risk…" 128 There is one further diving case, Waverley Municipal Council v Swain [2003] NSWCA 61. But before turning to that decision, it is appropriate to refer to a number of other authorities, not involved with swimming or diving but in which the obviousness of the risk has played a significant part in the determination of whether there had been a breach of a duty of care. 129 Waverley Council v Lodge (2001) 117 LGERA 447 concerned a person who had fallen on an area of rock between a rock pool and a wading pool as he was walking towards concrete steps which led to a landing and then to further steps up to the main beach promenade. In reversing the decision of the trial judge, Bryson J, with whom Meagher and Heydon JJA agreed, referred (at 458 [31]) to the application of the Shirt calculus in Romeo and noted the influence on the reasonable response to the foreseeability of the relevant risk of the obviousness of that risk to the relevant entrants including Ms Romeo. Given the nature of the tide and the location where Mr Lodge fell, Bryson J observed (at 439 [34]) that the likelihood that rocks may be slippery was obvious to any reasonable adult "with even elementary knowledge of the physical world and the margin between land and sea. The kind of danger which may be present is, for practical purposes, obvious to all." 130 His Honour thus concluded (at 460 [37]) that "the response of the reasonable person in the position of the appellant would be to do nothing, in the situation of control which I have found, and to leave persons who walked on rock to perceive and avert the risk themselves. If that reasonable person pursued his thinking to the point of defining a reason for so deciding, the reason would be that the risk was obvious to any reasonable adult, who could look about and see where he was walking and whether it was safe. In my view it would not be the response of a reasonable person to decide to erect signs which would do no more than to state the obvious for the information of persons who had much better access to the obvious from their own observation than a sign would give them." 131 Van Der Sluice v Display Craft Pty Ltd [2002] NSWCA 204 involved a plaintiff falling from a ladder and suffering head and other serious injuries. Heydon JA, with whom Meagher JA and Foster AJA agreed, upheld the Master's decision dismissing the plaintiff's claim upon he basis that, given the plaintiff's experience and skill, the defendant was entitled to assume that he would identify and eliminate relevant risks and could not reasonably foresee that the plaintiff would be harmed for failure to do so. In the course of his judgment, his Honour made the following observation ([74]): "…The fact that the higher up a ladder one moves the more care one must take for one's own safety is one of those simple facts affecting human existence in the physical world which adults in industrialised societies have learned by the time, or indeed well before the time, they have become adults. It is a fact as fundamental, as elementary, as clear and as well known as, for example, the fact that it is dangerous to behave boisterously near pots cooking on stoves, the fact that broken glass needs to be carefully handled when picked up, the fact that rocks along the seashore can be slippery, the fact that shells in the sand of beaches can be sharp, and the fact that when moving about rubbish dumps one must bear in mind the possibility that rubbish may be lying there. These are matters which no adult need be told about and which any adult can be trusted to guard against the dangers of because it is part of the equipment of all normal adult human beings. All citizens can safely and reasonably assume that each normal adult human being acting autonomously and voluntarily will not incur unnecessary and blatantly obvious risks." In my respectful opinion there can be added to his Honour's examples conduct which is so obviously and inherently risky that it is dangerous to dive into water unless one is satisfied that the depth of water into which one proposes to dive is sufficiently deep to enable that dive to be executed safely. And that this is so at the point at which one proposes to dive. 132 I next turn to the seminal decision of the High Court in Ghantous v Hawkesbury City Council (2001) 206 CLR 512. The plaintiff was a pedestrian who tripped and fell when walking along a concrete footpath. Erosion had resulted in subsidence of the earth in some places so that the verge adjoining the footpath was approximately 50mm below the level of its concrete surface. The plaintiff had stepped aside to allow others to pass and, in so doing, had placed her foot so that it was partly on the concrete and partly on the lower verge thus causing her to fall. The High Court held that the facts disclosed no negligence by the council because the footpath was not unsafe for a person exercising ordinary care. When dealing with pedestrians, Gaudron, McHugh and Gummow JJ observed (at 581 [163] citations omitted) that "such persons are more able to see and avoid imperfections in a road surface. It is the nature of walking in the outdoors that the ground may not be as even, flat or smooth as other surfaces. As Callinan J points out in his reasons … persons ordinarily will be expected to exercise sufficient care by looked where they are going and perceiving and avoiding obvious hazards, such as uneven paving stones, tree roots or holes. Of course, some allowance must be made for inadvertence. Certain dangers may not readily be perceived because of inadequate lighting or the nature of the danger … or the surrounding area…In such circumstances, there may be a foreseeable risk of harm even to persons taking reasonable care for their own safety. These hazards will include dangers in the nature of a ' trap ' or, as Jordan CJ put it, 'of a kind calling for some protection or warning '. In Romeo , Toohey and Gummow JJ noted in a different context that the care to be expected of members of the public is related to the obviousness of the danger. Kirby J pointed out in the same case that even an occupier of premises ' is generally entitled to assume that most entrants will take reasonable care for their own safety '. Each case will, of course, turn on its own facts." 133 The reference in the above passage to Romeo involving a different context is a reference back to a consideration by their Honours of a duty owed by an occupier of private land to various classes of entrants. When dealing with the associated question of the duty of a highway authority, their Honours observed (at 527 [148]) that the '…formulation of the content of the duty of care in this field [namely, the duty of a highway authority such as a local government council to road users] should not further pursue any analogy between occupation of privately owned land and the management and control by statutory bodies of land set aside for public use and enjoyment. The rights involved in this litigation are different in nature and degree to those enjoyed by visitors or entrants to or upon the scenic coastal reserve in Romeo , or the Basin swimming area at Rottnest Island". 134 Their Honours then considered that the better course was to give the duty of care of a highway a content reflecting what Mason J had said in Shirt (at 47-48). Nevertheless, it has not been suggested that the duty of care in cases such as the present should reflect any different content. Hayne J pursued a similar theme when he said in Brodie v Singleton Shire Council at 625-626: "303 The analogy between a statutory authority having care and management of a structure or facility, and the private occupier of land, is imperfect. Both have power to control the state of the place to which others resort. Both may, in that sense, be said to have the care and management of the place and it may very well be that it is only the owner or the statutory authority that has the power to remedy any defects in, or remove hazards from, the place or facility in question. But unlike the private owner, the statutory authority cannot wholly bar access to the facility it controls. The public commonly have access to it as of common right. The statutory authority can warn of hazards but, unlike the private occupier, the statutory authority cannot shift responsibility for the detection and avoidance of hazards by exacting special terms from those who enter. The private occupier of land, whether for reasons of economy or ease of mind, may choose permanently to bar access to the facility it controls, or at least it cannot do so as readily as can the private owner. 304 Moreover, in most cases the private owner of land will be relatively easily able to inspect that land for sources of danger to likely entrants. The occupier of large remote areas of land confronts much less likelihood of entry by others than the occupier of smaller areas in more frequented parts of the country. But a statutory authority, particularly a highway authority, may be responsible for the care and management of a diverse group of facilities that are spread widely. Although it will ordinarily have employees, they may not be numerous or skilled enough to detect risks. The task of inspecting all of the facilities for possible sources of danger will often be very large. Thus, if analogies are to be drawn, they are even less apt in the case of roads than they may be in relation to a confined, relatively small, structure like a jetty. Roads cannot readily be enclosed. Inspection of roads is a much larger task than inspecting a jetty. Moreover, it cannot be assumed that an authority will always be provided with money enough to employ those who would be needed to carry out the necessary inspections and it, unlike the impecunious private owner of land, cannot resolve the difficulty by selling the facility. 305 Account must be taken of these differences from the position of a private occupier of land in deciding what duty of care a statutory authority owes." 135 In a different factual context, the obviousness of the relevant risk was decisive to the High Court's agreement in Woods v Multi-Sport Holdings Pty Ltd (2002) 208 CLR 460 with the trial judge that there had been no breach of the defendant's duty of care. The plaintiff had suffered serious injury to an eye whilst playing indoor cricket at a facility owned and operated by the defendant. Although certain equipment was provided, helmets were not. It was held that reasonable care did not require the defendant to warn of the specific risk of eye injury from being hit by a ball, which was an obvious risk of the sport in question. In that context Gleeson CJ referred to the comment of Kirby J in Romeo, which I emphasised in the paragraph of his Honour's judgment extracted in [93] above. The Chief Justice then said (at 474 [45]): "It is right to describe that observation as a comment. It is not a proposition of law. What reasonableness requires by way of warning from an occupier to an entrant is a question of fact, not law, and depends on all the circumstances, of which the obviousness of a risk may be only one. And, as a proposition of fact, it is not of universal validity. Furthermore, the description of a risk as obvious may require closer analysis in a given case. Reasonableness would not ordinarily require the proprietor of an ice skating rink to warn adults that there is a danger of falling; but there may be some skaters to whom such a warning ought to be given. Nevertheless, as a generalisation, what Kirby J said is, with respect, fair comment…" 136 Kirby J (at 500 [127]), albeit dissenting in the result, nevertheless agreed with Gleeson CJ that his comment in Romeo "…did not amount to a universally applicable rule of law. It was not intended to be. Yet, as this Court has seen in several recent matters, it has been taken out of the context in which it appeared and elevated to a universal rule. I would adhere to what I said, read in the context of Romeo . That was a case where the proposition propounded by the claimant was that a warning sign should have been erected on the edge of an elevated cliff in a natural headland of a public car park, to the effect that it was dangerous to approach the edge. Such proposition had large consequences for every cliff in a natural setting on Australia's huge coastline. To suggest that such a warning ought to have been erected was, in my opinion, neither reasonable nor just in the circumstances of that case." 137 His Honour continued in these terms (at 500): "128 Obviously, that proposition could not apply to every situation of potential risk, so as effectively to abolish the need for warnings altogether. It could not apply, for example, to relieve a risk-creator simply because the risk was obvious. In a sense, the greater the risk, even if obvious, the greater may be the obligation of the party in control of it to warn others about it. Take the occupier with a deep hole in the middle of the path that in darkness could become a great danger. Take employers who must warn employees of risks, taking into account possibilities of 'inadvertence or carelessness' on the part of the employee. Or take the manufacturer of cigarettes. Apart from any statutory obligations that might apply, it could not seriously be suggested that such a manufacturer was relieved of the duty to warn because the risk of cigarettes to health is now 'obvious'. The duty to warn depends on the circumstances of the case, not just a suggested lack of 'obviousness' of the risk." (emphasis added) 138 Although it is trite as Kirby J says, that the duty to warn or more accurately, any breach of the duty to exercise reasonable care by a failure to warn depends on the circumstances of the case, it is important to note that his Honour's examples were, as the penultimate sentence of the passage from his judgment cited above makes clear, related to situations where the defendant is in control of the activity or situation which creates the risk and the risk is "obvious" often only with the benefit of hindsight. 139 In the present cases, it was submitted on behalf of the defendant public authorities that the risk of diving into water of unknown but variable depth was not "obvious" as a matter of hindsight but as a matter of foresight as that risk was inherent in the nature of the very activity undertaken by each plaintiff. Furthermore, it was submitted that in no relevant sense were the public authorities in control of the situation as they were not the creator of the facts and circumstances that gave rise to the risk. In my opinion, these submissions have considerable force especially as the relevant danger constituted by the variable water depths was created by naturally occurring phenomena (such as movement of the sand bed) over which the authorities had no control. 140 The decisiveness of the obviousness of the risk to the question of breach of duty adumbrated in Ghantous has been followed and applied in this Court in any number of pedestrian injury cases since that time: see Hastings Council v Giese [2003] NSWCA 178 at [18]; Roads & Traffic Authority of NSW v Jackson [2003] NSW CA 40 (special leave refused). It has also been applied in a diving case, Waverley Municipal Council v Swain [2003] NSWCA 61 (special leave granted). 141 In Swain, the respondent was rendered a quadriplegic as a result of diving into the water at Bondi Beach in small surf. A jury found for the plaintiff on the basis that the defendant Council had breached its duty in care in failing to warn of the risk of the appellant hitting his head on a sandbar. It was held by Spigelman CJ (Handley and Ipp JJA agreeing on this point) that there was no evidence to justify such a finding. 142 When dealing with the issue of breach of the respondent's duty of care by reason of failure to warn, the Chief Justice ([97]) noted that one factor which generally arises in a warning case is the degree of obviousness of the risk which, his Honour observed, was relevant to the reasonableness of the conduct suggested to have been necessary to avoid or minimise the risk. After referring to Prast, Harper and a number of other authorities where it was held that there was no breach of a duty of care due to the obviousness of the risk including the fact that the risk in question was inherent in the particular activity undertaken, the Chief Justice observed ([100] (omitting citations)): "Classification of a risk as 'inherent' or equivalent, considers only one factor in determining whether a duty of care exists, or identifying the appropriate standard of care, or determining breach. The whole of the circumstances need to be considered, even in the case of an inherent risk." 143 At [101] his Honour noted that "[t]he case law on warning sometimes contrasts the issue of 'obviousness', with a danger said to be 'hidden', in the sense that the particular risk was not observable on the relevant occasion: Nagle v Rottnest Island Authority was such a case." 144 His Honour then referred to the passage in the joint judgment in Nagle at 427-428 in which reference is made to the finding of the trial judge as to the obscuring of the rock due to sun glint or glitter pattern. It is apparent that the Chief Justice considered that that finding constituted Nagle as a case of a hidden rather than an obvious danger. 145 Although his Honour did not comment on its correctness, he observed in relation to the decision of Bell J in Vairy that it was one "where the risk of diving into the sea from the rock platform above a beach varied considerably because of the movement of the sand leading to significant variations in the depth. Although the ocean floor was generally visible, her Honour held that it was not possible to gauge accurately the depth of the water from the rock platform." It would appear that it was this last-mentioned factor that rendered the relevant risk " hidden ". 146 With respect, the risk so identified by the Chief Justice in the judgment of Bell J does not state her Honour's conclusion with complete accuracy. The particular risk with which Mr Vairy was confronted was the danger of hitting his head on the sandy bottom. That bottom was observable. What was not observable was the variable depth of the water. That was the danger that her Honour considered to be hidden. 147 The Chief Justice then continued ([104]): "The weight to be given to 'obviousness' as a consideration in determining what reasonableness requires of a person who has a duty of care, is complicated by a further consideration. To what degree is it appropriate for a person who owes such a duty to assume that persons to whom the duty is owed will take reasonable care for their own safety? Alternatively, to what degree should the person take into account the possibility of inadvertence or negligent conduct on the part of others? This is a matter on which there is distinctly different approaches on the part of judges when determining questions of reasonableness …Nevertheless it remains a real question as to when it is appropriate to warn a person about something that person already knows, as appears to be true in the present case. 148 Having referred to that part of the judgment of Kirby J in Romeo extracted in [93] and the comments thereon by both Gleeson CJ and Kirby J himself in Woods, the Chief Justice noted that since 1986 the law had "progressed" by giving greater weight to the possibility of inappropriate conduct on the part of others. However, as a result of the observations of the High Court in Romeo and those of Gleeson CJ and Kirby J in Woods, as well as those in Ghantous to which I have already referred and cases in this Court which have followed it, his Honour noted ([114]) that it: "now appears possible to identify a change in the law in the other direction i.e. greater weight is being given to the proposition that people will take reasonable care for their own safety." 149 The Chief Justice then continued: "116 Relevantly to the present case, in my opinion, no person attending an Australian beach could fail to know that there are sudden variations in the sand level under water. The formation of the ocean floor at the edge of the water is subject to continuous movement of currents and the pounding of waves which causes undulation in the sand formation that can, sometimes, become quite steep. There is an element of hidden danger involved in the inability to see the formation of the floor beneath an oncoming wave. Unlike the slip and fall cases e.g. Ghantous, Standing, McGuinnes and Byrnes , the Council officers are in a better position to assess the risk because they have elevated viewing platforms. 117 However, unlike many other cases of hidden danger (such as those referred to in Brodie v Singleton Shire Council at [163] or in Nagle or Vairy ) the fact that any danger was hidden was itself quite apparent to the swimmer. He or she could see the breaking wave and realise that whatever was underneath was hidden. 118 I would asses the degree of obviousness of the risk of diving into a wave without knowing the formation of the floor as high, albeit not at the end of the spectrum described as 'inherent in body surfing' in Prast v Cottesloe at [32] or as 'part and parcel of the recreation' in Mountain Cattlemens' Association v Barron at 309. This factor is, therefore, entitled to weight in deciding what a reasonable Council should have done with respect to warning, but is not determinative." 150 As I understand the Chief Justice, it was the fact that the degree of obviousness of the risk did not reach the level of being blatant which prevented that fact from otherwise being the determinative factor in resolving the issue of breach. Thus, at [119] his Honour considered that the outcome of the case turned on the absence of evidence as to the reasonableness of the content and location of the warnings that would be required to reduce the relevant risk. In this respect, he distinguished the present case involving a beach exceeding 1km in length to the cases of Nagle and that of Mr Vairy where a warning sign could be located at a specific rock ledge. Accordingly, it was the festooning of Bondi Beach with signs which ultimately determined the outcome of the case: cf Harper at [148]; Lodge at [35]. 151 The question of obviousness of the risk has, however, been determinative in other cases not involving diving. Thus, in University of Wollongong v Mitchell [2003] NSWCA 94, the appellant was injured when she attempted to resume her seat in a theatre occupied by the defendant but failed to notice that the seat had retracted whereupon, not having pulled the seat down, she fell and was injured. At [10], Meagher JA observed that the failure of a defendant to erect signage was becoming an increasingly popular head of negligence amongst plaintiff litigators. Having noted that such a failure may in some circumstances amount to negligence, his Honour considered that there were limits to the doctrine. Reference was made to a number of authorities including Lodge. His Honour concluded at [13] that "(i)t must be the law that there is no need to warn against any danger whose existence is glaringly obvious, nor to warn persons who know full well what the dangers are: Waverley Municipal Council v Swain [2003] NSWCA 61." 152 Giles JA posed the relevant question as to whether a reasonable person in the position of the appellant, by way of response to the risk that an entrant to the theatre would suffer injury in the manner sustained by the respondent, would provide an appropriate warning sign. His Honour answered the questions in these terms ([33], omitting citations): "An occupier is entitled to assume that most entrants will take reasonable care for their own safety… Where the question is one of warning of a foreseeable risk of injury, if the risk is obvious to an entrant exercising reasonable care for the entrant's own safety it is not necessary that the occupier warn of it. In Waverley Municipal v Swain at [114] Spigelman CJ suggested that there could be identified a change in the law whereby greater weight is being given to the proposition that people will take reasonable care for their own safety. There are tides in the law, as in all affairs of man. It may be that a favourable tide has begun to ebb, or it may be that it only appears so because an increase in warning cases has brought to prominence the concerns voiced by Bryson J in Waverley Municipal Council v Lodge at [35]. Be that as it may, the reasonable man in the position of the appellant can take account of what would have been known or apparent to entrants to the theatre, and of the reasonable care they would then exercise for their own safety." 153 Their Honours voiced concerns as to the correctness of the decision of this Court in Burns v Hoyts Pty Ltd [2002] Aust Tort Reports 81-637 which involved a similar factual situation. Giles JA considered that Burns was distinguishable on its facts. Meagher JA considered that it "trembles on the brink of error" and so it did as this Court's decision was reversed by the High Court in Hoyts Pty Ltd v Burns (2003) 201 ALR 470. McHugh, Gummow, Hayne and Callinan JJ held that there was no basis for this Court intervening to reverse the decision of the trial judge in favour of the defendant. 154 Kirby J considered a number of cases on warning signs including Nagle, Romeo and Woods. With respect to the duty to warn entrants of premises concerning present risks (or more accurately the duty to exercise reasonable care by providing a warning), his Honour accepted that whilst Nagle stands, it could not be said that there is no such obligation. To decide whether in a particular case a warning notice is required to avoid a breach of the duty of care, his Honour considered that it was necessary to take into account the social considerations that the law is seeking to advance. In the context of an occupier vis-à-vis an entrant, his Honour identified the following considerations as relevant to the obligation to provide a warning notice ([71]): "…(1) whether the occupier has an economic or other interest in the entry of the plaintiff; (2) whether, because of previous incidents, public discussion or otherwise the occupier could be expected to know of any particular risks against which warnings should be given; (3) whether there was any hidden feature of the place or activity that might not be plain to an ordinary entrant but which should be known to, or reasonably discoverable by the occupier, calling for a warning; (4) whether, if the risk eventuated, the consequences would be likely to be minor or significant for the person affected; (5) whether the imposition of a requirement to give a notice could be confined to a particular place or places or would have large implications, costs and other consequences; and (6) whether the nature of the activity in question was such as to render the presence of a sign irrelevant to the actual prevention of injury." 155 Although his Honour did not suggest that the above list was exhaustive, it is clear that he that considered that the obviousness or hidden nature of the risk was but one of the considerations required to be taken into account. It should further be noted that his Honour was speaking in the context of the liability of a private occupier of premises rather than the position of a public authority to which, according to Hayne J in Brodie (at 625-626 [303]-[305]), different considerations apply in deciding the scope of the duty of care owed by such an authority. 156 Although not dealing directly with questions of obvious risk, the shift referred to by Spigelman CJ in Swain and noted by Giles JA in Mitchell was recently reflected in the following observations of Mason P, with whom Hodgson JA and myself agreed, in Frances v Lewis [2003] NSWCA 152 (at [40]): "Foreseeability of risk of injury is not determinative of breach of duty of care. …The duty is one of reasonable care, not whether safety could have been improved by some modification. The duty is not confined to one owed to those who are careful for their own safety, but it is relevant to take into account that plaintiffs are themselves expected to act reasonably and take care for their own safety when determining what is reasonable." 157 In my opinion, this shift towards personal responsibility for one's conduct, especially in the context of sporting and recreational pursuits where the risk of injury is obvious, accords with current expectations of the community as reflected in legislation such as the Civil Liability Act 2002 (particularly Divisions 4 and 5 of Part 1A). This reference to the Civil Liability Act is not to suggest that the present appeals, both based upon common law, are somehow to be subjected to the flavour of the Act to the effect that, as a general proposition, individuals ought to assume responsibility for their own conduct. Such a suggestion has no foundation in legal principle, a point recently made by Mason P (in dissent) in Harriton (by her tutor) v Stephens; Waller (by his tutor) v James; Waller (by his tutor) v Hoolahan [2004] NSWCA 93 at [164]. Rather, I simply wish to cite the Act as another indicator that the shift towards personal responsibility, noted by Spigelman CJ in Swain, shows no sign of retreat. See also Uzabeaga v Town of Cottesloe [2004] WASCA 567 at [65]-[68] per Steytler J. 158 But the shift is also a product of the High Court's emphasis on the reasonableness of a defendant's response to a foreseeable risk. As Gleeson CJ pointed out in Tame v New South Wales (2002) 211 CLR 317 at 332 [14], reasonableness is "at the heart of the law of negligence" and is "judged in the light of current community standards. As Lord Macmillan said in Donoghue v Stevenson , 'conception[s] of legal responsibility …adap[t] to … social conditions and standards' " 159 So also in Dovuro Pty Ltd v Wilkins (2003) 77 ALJR 1706 at 1712 [340]. McHugh J emphasised that "(i)f negligence law is to serve any useful social purpose, it must ordinarily reflect the foresight, reactions and conduct of ordinary members of the community …To hold defendants to standards of conduct that do not reflect the common experience of the relevant community can only bring the law of negligence, and with it the administration of justice, into disrepute. 160 To similar effect, in Harriton the Chief Justice (at [20]-[21]), albeit in a context quite different to that of the present cases, emphasised that the law of negligence recognised the need for a duty of care to reflect current community values and standards. Obvious and Inherent Dangers 161 At this point it is appropriate to comment that, according to my research, none of the Australian cases attempt to define what is meant, at least generally, by an obvious risk. This is not to say that the authorities referred to above are inconsistent in approaching the question of whether a risk is, in fact, obvious in a given circumstance. However, I see no reason not to adopt the definition found in the commentary to §343A of the Restatement (Second) of Torts (1965) (Rest 2d Torts §343A). This definition is consistent with the Australian authorities discussed above which have emphasised the importance of an individual taking care for his or her own safety. In the commentary, "obvious" is defined as follows: " 'Obvious' means that both the condition and the risk are apparent to and would be recognized by a reasonable man, in the position of the [plaintiff], exercising ordinary perception, intelligence, and judgment." 162 In this definition "condition" refers to the factual scenario facing the plaintiff. Thus, in a diving case the condition might typically be the fact that the plaintiff is faced with water of unknown depth. Under such a condition the risk would be that diving into the water (while the depth remains unknown) might result in (serious) injury. This risk would be considered obvious if, in the context of the case, it was perceptible to a reasonable person in the position of the plaintiff that if you do not know the depth of a body of water into which you are about to dive, then to dive into such water under such conditions inevitably brings with it the risk of injury. 163 It is also appropriate, having defined an obvious danger, to draw a distinction between an "obvious danger" and an "inherent danger". The point is that an obvious danger is not necessarily an inherent danger. Just as a danger may be both obvious and inherent, it may, dependent upon the circumstances, also be obvious and non-inherent. For that matter, a hidden danger need not necessarily be a non-inherent danger: a danger could, in a given case, be hidden and inherent. Accordingly, the fact that a danger is (or is not) inherent will not be a clue to whether such a danger is obvious. However, as will be explained below, the fact that a danger is inherent or non-inherent may, in some circumstances, be a factor of weight in determining if a reasonable response of an occupier under a duty of care toward an entrant involves the need (or duty) to warn of the danger. 164 An inherent danger is a danger (or risk) attaching to a condition or activity that cannot be removed by the exercise of due care: Prast at [35]; Rogers v Whitaker (1992) 175 CLR 479 at 483,491. That is, by exposing oneself to a condition or activity involving an inherent danger one has thereby become subject to the possibility of the danger crystallising. For example, in Prast, Ipp J (at [32]) explained that the risk of being dumped by a wave while bodysurfing was not only obvious, but also inherent since, once a bodysurfer has caught a wave, he or she has, as it were, become subject to the will of the wave which, even in normal surf conditions, may unexpectedly dump them. Accordingly, even the exercise of reasonable care on the part of the surfer will not remove this danger. Rogers provides a further example, but from the perspective of a hidden danger. In that case the risk of surgery to one eye was found to carry with it the inherent danger of both the patient's eyes becoming subject to sympathetic ophthalmia and consequently blindness. This danger, while inherent, would seem to have also been a hidden danger since a reasonable patient without specific medical knowledge would not, as at least a matter of commonsense, be aware of the danger. Hence the necessity for a warning. 165 Of particular concern in the context of the present case is the danger associated with diving into water of unknown depth. Generally speaking such a danger will be non-inherent where the depth of water is constant or stable; for example, in a swimming pool. By ascertaining either the depth of the water before diving or by the occupier giving a warning (or an indication of the depth) under such constant conditions, the danger (be it hidden or obvious) can be eliminated all together. 166 Further, a danger may be non-inherent where there exists an object below the surface of the water blocking the trajectory of a dive. Such a danger may perhaps also be hidden if, on the facts of the case, the object is obscured from the diver. One example, considered below, is the United States case of Jackson v TLC Associates (1998) 706 N.E 2d 460. In such circumstances the relevant factor making the danger non-inherent is not the stability of the body of water but the fact that the location of the object can be determined and avoided. 167 However, where the dive is to be undertaken in an environment where the depth of water is subject to change at short notice and without reasonable warning, then the danger (individual circumstances depending) will generally be an inherent danger. That is, under such conditions, the giving of a warning or the checking of the depth of the water prior to diving may not remove the risk. For instance, generally a dive into the sea will be subject to the surge, swell, tide and the continuous rise and fall of the waves. Further, the seabed itself may be undergoing change, sometimes at short notice, as sands are washed about as the sea's moods and tempers constantly fluctuate. In such cases, particular circumstances depending and irrespective of the danger being obvious or hidden, the danger will be inherent. 168 The question may then be asked "what utility comes from determining if a danger is inherent or non-inherent?". In the first place, I would suggest that if the danger is found to be both obvious and inherent, then this may serve to add weight to an occupier-defendant's argument, when the time comes to consider the application of the Shirt calculus to the facts, that the reasonable response to the relevantly foreseeable risk was to do nothing and, in particular, not to warn. The reason for such a response is that no amount of due care through warning could have removed the danger: see Prast at [29]-[45]. If the danger is obvious but non-inherent, the fact that the danger could be removed by warning (and perhaps equally by the entrant checking) may be a relevant consideration when determining if the scope of the duty of care involved a duty to warn. However, the inherent nature of the risk would always seem to be a secondary factor and generally subservient to whether the danger was hidden or obvious in the first place. Use of the phrase " duty to warn " 169 In Woods at 500, extracted above at [136]-[137], Kirby J spoke in terms of an occupier's "duty to warn" as part of a general discussion as to when a court may, or may not, impose such a duty. The phrase "duty to warn" and phrases to similar effect, have also gained currency in a number of other negligence cases: for example, Romeo at [48], [123]; Swain at [96], [177]; Prast at [32], [43] and Curley at [15]. Further, as will be seen below, the phrase has also found favour in the Supreme Courts of the States of the United States. In my opinion it would be erroneous to read a reference to a "duty to warn" in the authorities as being a reference to a duty different to the duty of an occupier to exercise reasonable care in the face of a reasonably foreseeable risk of injury. They are one and the same. 170 The phrase "duty to warn" is therefore no more than a shorthand or convenient way of referring to the situation where it is claimed that the reasonable response of an occupier subject to a duty of care, in the face of a reasonably foreseeable risk of injury, can only be discharged by the giving of a warning, commonly by displaying signage. It is in this sense that I use the phrase in this judgment. The phrase perhaps gains its convenience from the fact that in numerous negligence cases, where an entrant-plaintiff has suffered injury, it is commonly pleaded, and thus subject to determination by the court, that the occupant-defendant was negligent insofar as it failed to warn the entrant of a reasonably foreseeable risk of injury. That is, it is pleaded that the discharge of the occupier's duty of care as a reasonable response to a foreseeable risk must, as a necessary minimum, be by way of a "duty to warn". 171 Of course this is not to suggest that in every entrant-occupier case the only appropriate response (or the "always appropriate" response), so as to discharge a duty of care, is to warn. On a given set of facts it could be the case that a warning may not go far enough to satisfy the duty. Perhaps in a given entrant-occupier case a prohibition upon entry, or a class of entrants such as children, may be the minimum action necessary to discharge the duty. 172 Equally, and I have touched upon this point in my discussion of Nagle at [71] – [73] above, it may be that in a given case an occupier, under a duty of care, is not under a duty to warn. That is, under the Shirt calculus, an occupier is required to make a reasonable response to the foreseeable risk so as to discharge his or her duty of care. However, a reasonable response may not involve any act on the part of the occupier: in other words, a "do nothing" response. This point was made by McHugh J in Dovuro at [38] where he observed that: "(a) defendant is not negligent merely because it fails to take an alternative course of conduct that would have eliminated the risk of damage. The plaintiff must show that the defendant was not acting reasonably in failing to take that course. If inaction is a course reasonably open to the defendant, the plaintiff fails to prove negligence even if there were alternatives open to the defendant that would have eliminated the risk." In the same vein see Heydon JA's remarks in Van Der Sluice , reproduced above at [72]. Some United States authorities 173 The United States authorities relating to plaintiffs injured in natural aquatic environments are conveniently reviewed by D P Connaughton, J O Spengler and B P Burket of the University of Florida in "Liability and Warnings in Natural Aquatic Environments: A Case Law Analysis" (2002) 12 Journal of Legal Aspects of Sport 61; cf Fitzgerald and Harrison, "Law of the Surf", (2003) 77 ALJ 109. A further useful survey of cases, coupled with an informed discussion of the relevant principles, is to be found in §343A of the Restatement (Second) of Torts (1965). 174 The trend of the United States authorities would seem to be as follows: a) the courts tend to define the relevant risk as being that of diving into water of unknown depth. They reject the idea that the risk should be more narrowly defined so as to render it one that is hidden; b) where the risk is that the bottom of the body of water where the plaintiff dives is too shallow, then this is generally considered to be an obvious (and often inherent) risk: i.e. the very existence of a body of water (the depth of which the plaintiff does not know) warns of this danger; c) the risk will not necessarily be either obvious or inherently dangerous when there is something in the water between the surface and the bottom (such as a pipe), which is unknown to the diver: in this event the risk is more likely to be considered hidden; d) the natural phenomenon of sand being moved around by the current or the ebb and flow of the tide tends to be characterised as an obvious and often inherent danger; e) there is some dispute about whether an obvious danger means that the risk of injury is not foreseeable or whether it means that it is foreseeable but there is no duty to warn. 175 Before discussing these principles it should to be noted that the United States cases need to be read with some care since, speaking generally, all a defendant-landowner needs to prove, so as to defeat a negligence suit based on an alleged failure to warn, is that the relevant risk was obvious, or ought to have been, to the plaintiff (the US common law "open and obvious doctrine", also known as the "known and obvious doctrine"). 176 As discussed extensively above ([55]ff), the law in New South Wales involves a broader consideration of the facts. Thus the Shirt calculus must be applied in determining the reasonable response to a foreseeable risk so that the obviousness of that risk is but one factor to be weighed in the balance: see the comments of Heydon JA in Van Der Sluice at [74] (extracted above at [119]) and those of Kirby J in Woods at 500 (extracted above at [126]) and the remarks of the Chief Justice in Swain. However, as these extracts (and judgments) also make plain, this is not to say that, in a given case, the fact that a risk is obvious cannot be highly determinative in the determination of that response. That is (as seems sensible enough), in weighing up the relevant factors so as to determine a reasonable response, it may be the case that the existence of an obvious risk which is, or ought to be, known to the plaintiff may be highly determinative in deciding if the defendant had a duty to warn. In any event, and leaving aside the specifics of the "open and obvious defence", the foregoing principles can be illustrated in the cases considered below. 177 In Dowen v Hall (1989) 548 N.E. 2d 346, an adult guest dived into a natural lake from a pier owned by the defendants and was paralysed. The Appellate Court of Illinois upheld the trial judge's decision in favour of the defendant upon the basis that the danger of paralysis from diving was one that was open and obvious. McMorrow J, who delivered the opinion of the court, noted that the lake bottom was basically muck and sand at the time of the plaintiff's injury, the water was muddy and the plaintiff could not see the bottom of the lake more than three feet from the shoreline. The plaintiff was acquainted with swimming in natural lakes and knew that their depth varied. The dive he executed was a flat one as he was conscious of the necessity to avoid hitting the bottom. As to the nature of the risk of injury, his Honour observed (at 348 [4]): "In our view, the instant facts and the reasonable inferences which may be drawn from them demonstrate as a matter of law that the danger of paralysis resulting from a flat dive off a pier into muddy waters of uncertain depth in a natural lake is open and obvious to a reasonable adult. As the plaintiff himself was aware, natural lakes are of uneven depths at various points, and the muddy waters of the lake prevent a person from discerning the depth of the water. Thus a reasonable adult in the plaintiff's position would recognise that an attempt to execute a head-first flat dive into the lake, without prior awareness of the depth of the waters, might result in severe injury from hitting one's head on lake bottom. …Because the risk was open and obvious, the defendants had no duty to warn the plaintiff of that risk in the case at bar." 178 In Hagy v McHenry County Conservation District (1989) 546 N.E. 2d 77, the same Illinois court (differently constituted), rejected an appeal by a minor who had sued the owner of a creek for injuries sustained when he dived into the muddy water of the creek and was injured. It was held that the muddy water presented an obvious risk that it may be too shallow for the diver to execute a safe dive. Unverzagt J who delivered the opinion of the court, considered (at 85 [14]) that a head first vertical dive from a height into a creek of uncertain depth constituted an obvious risk and one which ought to have been appreciated by the 15 year old plaintiff. This was particularly so where the water was muddy which his Honour said "presented the obvious risk that it will be too deep for the non-swimmer or too shallow for the diver" His Honour also noted that soft sand on the bottom of a body of water shifts with currents and disturbances and is a condition that an adult reasonably could be expected to understand. 179 In Griebler v Doughboy Recreational, Inc (1991) 466 N.W 2d 897, a man suffered quadriplegia after diving into a backyard pool the depth of which he did not know. The Supreme Court of Wisconsin, reversing Wisconsin's appellate court, found that the danger of diving into a pool of unknown depth was open and obvious. In reaching this conclusion the court (Ceci J, with Abrahamson J concurring) made the following points. 180 First, Ceci J, at 901, stated that prima facie "diving into water of unknown depth is an open and obvious danger." That is, where the plaintiff is aware of the fact (or, to adopt the terminology of the court, "the condition") that a body of water is of unknown depth, then this (obviously) gives rise to the risk of hitting one's head if the water turns out to be too shallow to safely admit of the style of dive executed by the plaintiff. Accordingly, the existence of the condition known to the plaintiff gives rise to the risk of hitting one's head so as to create an open and obvious danger. 181 Secondly, Ceci J at 901(see also Abrahamson J at 903) expressly rejected an argument similar to one raised by the plaintiff in Vairy: that diving into water of unknown depth morphs from being an obvious danger to a hidden danger in circumstances where the plaintiff has observed others undertaking such a risk (see above at [44](i)&(k)). His Honour, in an attempt to explain the reasons for rejecting such an argument, drew an analogy with industrial negligence: a negligent industry practice is not made less negligent merely because it is widespread. In my opinion, the underlying principle here is that the court, in determining if a risk is open and obvious, considers the matter objectively. That is, the fact that a plaintiff may consider there to be no obvious risk, especially where that belief flies in the face of a foolhardy (even if popular) mode of behaviour which, at the very least, should have been apparent to the plaintiff, ought to be disregarded when determining the reasonable response of the defendant to that risk. This point undergoes a fuller development in O'Sullivan v Shaw (2000) 726 N.E 2d 951 considered below. 182 In Bucheleres v The Chicago Park District (1996) 665 N.E. 2d 826, the Supreme Court of Illinois, reversing the Appellate Court, held that the defendant had no duty to warn the plaintiffs, who were injured when they dived into Lake Michigan from concrete seawalls, of the dangers involved in diving into a natural body of water because such danger was open and obvious. McMorrow J, who delivered the opinion of the majority, noted (at 831) the argument of the defendant that the court should reaffirm "long-standing principles which recognise that owners and occupiers of land generally owe no legal duty to take precautions or warn against risks from 'open or obvious' conditions present on the land…Specifically the Park District argues that it owes no duty to protect experienced, adult swimmers who injure themselves by diving into a natural body of water without first learning the water's depth and the bottom's composition" 183 The majority, after analysing the various arguments at bar, affirmed (at 832) "the continued viability of the open and obvious doctrine in the analysis of the landowner's duty to persons injured while on the landowner's property" His Honour continued in these terms: "In cases involving obvious and common conditions, such as fire, height and bodies of water, the law generally assumes that persons who encounter these conditions will take care to avoid any danger inherent in such condition. The open and obvious nature of the condition itself gives caution and therefore the risk of harm is considered slight; people are expected to appreciate and avoid obvious risks." 184 The plaintiffs sought to distinguish cases such as Dowen and Hagy (in which it was held that bodies of water were ordinarily considered to be open and obvious conditions and thereby carried their own warning of possible danger) by analysing the tort duty and focussing on what the defendant knew or ought to have known i.e. where the harm to the plaintiffs was foreseeable. In rejecting that argument, his Honour said (at 834): "We reject plaintiff's argument that the appellate court's reasoning that the instant cases fall outside the scope of the general rule regarding open and obvious conditions on land. On the threshold issue of whether the lake around the seawalls adjacent to the beaches was an open and obvious condition of potential hazard, it is undisputed that the water levels of Lake Michigan fluctuate and that storms and strong currents change conditions on the bottom of the lake and the surrounding shores. Plaintiffs do not argue that the concrete seawalls in issue were designed for diving; …We conclude that Lake Michigan, as a large body of water with uncertain or fluctuating water levels and bottom composition, presents open and obvious risks to lake front patrons who dive from concrete seawalls into the lake." 185 Having affirmed the applicability of what was referred to as the "open and obvious doctrine", his Honour then considered (at 836) the effect of that doctrine on what he referred to as "the traditional factors that are relevant to the court's imposition of duty". Those factors, reminiscent of the Shirt calculus, included the likelihood of injury, the reasonable foreseeability of such injury, the magnitude of the burden of guarding against injury, and the consequences of placing that burden on the defendant. Having emphasised that simple foreseeability of injury is not, and has never been, the issue of whether the law imposes a duty in negligence, his Honour concluded that no duty should be imposed upon the Park District. 186 Harrison J dissented. He argued that it was wrong to treat the "open and obvious danger" factor as a doctrine rather than as one element to be considered in determining whether a duty to warn was owed. His Honour observed (at 840): "Whether a duty exists in a particular case involves consideration of whether the injury was reasonably foreseeable. That, however, is not the end of the inquiry. Because the existence of a duty turns, in large measure, on public policy factors, the court must also take into account the likelihood and severity and of the injury, the burden of guarding against the injury, the consequences of placing that burden on the defendant …These considerations must be weighed against each other. Accordingly, a duty of reasonable care may be imposed on a defendant even though the danger of injury is remote where the gravity of the injury would be great and the burden of protecting against it slight." 187 After rejecting the "open and obvious" doctrine as effecting a general rule, his Honour continued: "My colleagues assert that injuries of the kind sustained by the plaintiffs here were not reasonably foreseeable because Lake Michigan is a body of water, and water is included in a litany of supposedly 'obvious' conditions that people are expected to protect themselves against. The problem with this approach is that it would effectively deny the existence of a duty whenever any body of water is involved. The particular circumstances of the case are rendered inconsequential, and the need for further application of the traditional duty analysis becomes moot." 188 In Jackson v TLC Associates (1998) 706 N.E. 2d 460, the Supreme Court of Illinois in an opinion delivered by Harrison J, reversed the Appellate Court and held in favour of a swimmer who sustained spinal injuries when he dived from the shoreline of a commercial public bathing beach into a lake. In this case, however, the plaintiff had dived into the water and collided with a submerged black plastic pipe that was a few inches below the surface and was used by the owners of the beach to adjust the water level of the lake. The Appellate Court had applied Bucheleres to the effect that an adult is expected to appreciate the risks of diving into a body of water that is murky and of uncertain depth as was the water in this case. However, the entry of summary judgment in favour the defendant by the Appellate Court had denied the plaintiff the opportunity of proving that he had hit his head on the submerged plastic pipe rather than the bottom of the lake. As there was an issue of fact as to what the plaintiff hit, it was necessary to set aside the summary judgment. 189 In the course of his judgment, Harrison J referred to the principle of Illinois law which holds that persons who own and occupy or control and maintain land are not ordinarily required to foresee and protect against injuries from potentially dangerous conditions that are open and obvious such as fire, height and bodies of water. However, it was recognised that the existence of an open and obvious danger was not a per se bar to finding that a defendant in those circumstances had a duty to exercise reasonable care. Shirt type factors were required to be taken into account. 190 The Supreme Court recognised that although a body of water, whether natural or artificial, is deemed to present an open and obvious danger, the open and obvious doctrine was not necessarily dispositive of the case. Cases addressing the "open and obvious danger of water" were premised on the notion that bodies of water posed two particular types of risk: the risk of drowning and the risk of injury from diving into water that is too shallow. As it was alleged that the plaintiff had hit his head on a submerged pipe whose location was variable and undetectable by swimmers, neither of those risks was an issue in the instant case. The existence of the pipe had nothing to do with the inherent characteristics of bodies of water but stemmed solely from the defendant's conduct. As a consequence the case was distinguishable from those such as Bucheleres. 191 O'Sullivan, a decision of the Massachusetts Supreme Court, concerned a man who suffered a spinal injury after diving headfirst into the shallow end of a backyard pool. The dive was executed in the dark of night such that the plaintiff did not know the depth of water into which he was diving. However, the existence of a diving board in the deep end was said to have been suggestive of the fact that the opposite end of the pool was shallow. The plaintiff argued that the landowners were under a duty to warn him of the dangers of diving into the shallow end of the pool. Lynch J, in delivering the opinion of the court, stated that in determining whether there was a duty to warn, the inquiry was to focus upon the reasonable conduct of the defendant, all the while assuming that a plaintiff could be expected to exercise reasonable care for his or her own safety. Accordingly, the question for determination was "whether the dangerous condition was, objectively speaking, so obvious that the defendant would be reasonable in concluding that an ordinary intelligent plaintiff would perceive and avoid it and, therefore, any further warning would be superfluous." 192 The court, making reference to Griebler, rejected the notion that, in determining if a risk was obvious, recourse should be had to the plaintiff's subjective beliefs. That is, the fact that a plaintiff believed that there was no risk, or that he or she had eliminated any risk (by, for example, being proficient at executing "flat dives" in shallow water) ought not to affect the landowners' duty in the face of an obvious danger. Lynch J (at 957), said: "However, under our law of premises liability, the standard for determining whether a landowner is relieved of a duty to warn is whether the dangerous condition complained of would be obvious to a person of average intelligence, that is, a visitor with ordinary perception and judgment exercising reasonable care for his own safety. That many people might engage in objectively hazardous conduct on the basis of a belief that it can be done safely does not affect our analysis of a defendant's duty of care under this standard if, in light of the obvious risks entailed by the activity, the belief in question, however prevalent it may be, must nonetheless fairly be judged unreasonable, if not foolhardy." 193 Finally, in Snilsberg v Lake Washington Club (2000) 614 N.W 2d 738 the Minnesota Court of Appeals considered a case where a plaintiff, the girlfriend of a yacht club's caretaker, dived, at night, off the shortest of three of the club's docks into water of unknown depth and collided with the bottom resulting in quadriplegia. There was evidence suggesting that the plaintiff's friends had jumped from the dock seconds before she executed her dive. No signage warned of the dangers of diving. In determining if the defendant owed the plaintiff a duty, the scope of which involved an obligation to warn, the court in finding that no such duty was owed made the following points. First, that the "landowner's duty to entrants does not include situations where the risk of harm is obvious or known to the plaintiff, unless the landowner should anticipate the harm despite the obviousness of the risk." (744) Second, that the risk associated with diving off the shortest dock into water of unknown depth was obvious, where the risk was characterised as being that of "diving into water of indeterminate depth" (746). The court equated this risk with the obvious risk of knowingly diving into shallow water. 194 To reiterate what I have said above, there is no general Australian doctrine to the effect that there is no breach of duty following an occupier's failure to warn an invitee or licensee (or even a trespasser) on the basis that the risk is obvious. The most that can be said in the Australian context is that the obviousness of the risk is but one factor to be weighed. However, this is not to say that such a factor, especially where the obviousness is of a particularly apparent nature, cannot be, in the estimation of the tribunal of fact, highly determinative (or actually determinative) in a given factual scenario. What do the authorities establish? 195 So long as this Court is bound to apply the Shirt calculus, it would be wrong to elevate the obviousness factor into some doctrine or general rule of law. Gleeson CJ and Kirby J in Woods and Spigelman CJ in Swain make this clear. All the circumstances must be looked at of which the obviousness of the risk is only one. Factors such as whether the risk is obvious to a young person as distinct from an adult will play their part in the balancing process required by the Shirt calculus. But all things being equal, the trend of authority does establish that diving (particularly from a height) into a natural body of water of unknown depth is an inherently risky enterprise. What Henry LJ said in Whyte, cited in [123] above, seems to me to be plain common sense. Although one can accept, in terms of the Shirt calculus, that the magnitude of the risk may be great in that quadriplegia is likely to be sustained if one's head hits the bottom of a water body that is too shallow to safely accommodate a particular dive, the degree of probability of its occurrence is low because the obviousness of the risk will by that fact alone generally encourage adult persons to avoid the risk in the first place by either not diving or by first testing the depth of the water. 196 Of course, one of the difficulties in the present cases is identifying the relevant risk. In Rosenberg v Percival (2001) 205 CLR 434 at 453 ([61]) Gummow J, in a medical negligence case in which it was alleged that the medical practitioner owed a duty to warn the patient of a material risk inherent in the proposed treatment, posed for himself the question "what 'risk' is being spoken of here"? His Honour answered it as follows: "Put another way, it is 'what are the facts and circumstances, the possibility of the occurrence of which constitutes that 'risk'? Once that question is answered one may turn to consider whether the risk is 'material'. Where the action is brought in negligence and the plaintiff is seeking compensation for injuries suffered, the relevant risk is the possibility that the proposed treatment will result in the injury that in fact occurred. It is not, for example, the risk that the patient will make an uninformed decision or choose the wrong option, although that may well underpin the rationale behind the duty." 197 If one asks in the present case: what are the facts and circumstances, the possibility of the occurrence of which constitutes the risk that Mr Vairy and Mr Mulligan will sustain significant injury if they dive into the sea or creek, as the case may be, then in my opinion the answer is - the unknown and variable depth of the water into which each proposes to dive. 198 In Vairy, Bell J held that the relevant risk was diving into water of variable depth in circumstances where that depth was not observable. At [168] of her judgment, her Honour said: "The risk that the water on any given occasion was not sufficiently deep to make diving safe was not necessarily apparent to a person standing on the rock platform at the dive location and looking into the water." As I understand her Honour's reasoning, that risk was not obvious. 199 In my respectful opinion, her Honour identified the relevant risk at too narrow a level of abstraction. The fact that a person in the position of Mr Vairy, standing in the dive location and looking into the water, could not actually gauge the depth of the water was what gave rise to the risk in the first place; namely, that there was a risk of injury if one dived into water of unknown depth which turned out to be too shallow. 200 In Mulligan, Whealy J held that what was obvious was the risk of striking a transient sand dune occurring naturally on the bed of a tidal creek of variable, and I would add, unknown depth. According to Mr Mulligan's case, the matter requiring a warning related to the presence of water of variable depth due to the formation of naturally occurring sand dunes in the creek bed. He submitted that his was a case where it was unlikely that the hazard constituted by the movement of the sand or bedforms resulting in the variability of the depth of the water would be readily perceived even by a person care for his own safety by testing the depth of the water. The hazard was, therefore, not obvious. 201 But it was the very fact that the depth of the water was variable and known to be such by Mr Mulligan that resulted in his Honour finding that the risk of diving into such water was an inherent or obvious risk which did not require the response of the authorities for which Mr Mulligan contended. Furthermore, the relevant hazard or danger was not the movement of the bedforms resulting in the variable depth of the water but the risk associated with diving into water of unknown depth. As Mr Mulligan was aware that the water was of unknown depth, the danger of diving into such water was, indeed, readily perceived by him and therefore obvious. 202 As I have attempted to make clear above, especially at [60]-[61] and [160], this is not to say that in every case where an obvious danger presents itself there can never be a duty to warn. Rather the point is that here, on the facts of both cases, it was not unreasonable for the defendants to fail to warn of the foreseeable risk of diving into water of variable and therefore, unknown depth. That is, this "omission" did not constitute unreasonable conduct in the circumstances of these cases. 203 Two further matters require attention. First, common to both cases was the fact that the variable depth of the water was due to naturally occurring phenomena. In the case of Vairy, Bell J held (at [108]) that the water adjacent to the rock platform would be of variable depth (apart from tidal movements) because of changes to the level of the ocean floor caused by littoral drift. The sand forming the ocean floor was constantly moving and shoals and channels were formed with the movement of the sand. Her Honour was satisfied (at [170]) that Wyong knew or ought to have known that the ocean floor adjacent to the rock platform varied in depth as a result of those movements. She also held that Wyong knew or ought to have known of the danger that the variations in the level of the seabed posed for persons diving from the rock platform. 204 In Mulligan, Whealy J (at [303]) noted that it was part of the natural condition of the creek and indeed of tidal estuaries throughout the world that the bed of the creek was made up of sand dunes that were influenced by the ebb and flow of the tide. He said: "Moreover, sand dunes of this kind come and go in what may seem to the casual swimmer to be a relatively random fashion. Sand dunes appear, disappear and reappear in different parts of the creek and ocean bed. They are sometimes large, other times they are not. They may be hard or soft." 205 For present purposes, I will assume that, like Wyong in Vairy, the public authorities in Mulligan knew or ought to have known of the variations in the sandy bed of the creek due to the natural ebb and flow of the tides to which I have referred. 206 In my opinion, this knowledge (or assumed knowledge) on the part of the defendants is neutralised by the fact that each of Mr Vairy and Mr Mulligan were aware that the water into which they were diving was not only of variable depth but also of unknown depth. It was those factors, as I have said, which made the risk of injury from diving into such water, obvious. As such, in the present circumstances, a reasonable response from the defendants did not require a duty to warn. The duty of care owed to the plaintiffs was not breached by the failure of any of the defendants to give any warning: the giving of a warning was not within the scope of their duty of care. 207 A more difficult issue relates to the experience of each of the plaintiffs. In the case of Mr Vairy he had knowledge both on the day in question, and from his previous visits to Soldiers Beach, that people dived from the rock platform seemingly without sustaining injury. It was these facts that caused Bell J to observe (at [170]): "The danger that identified (in addition to the general difficulty of estimating the depth of the water) is (i) that persons who have previously dived with safety may be misled by the belief that the depth of water will be sufficient to allow safe diving and (ii) persons such as the plaintiff who have observed people diving safely on other occasions may be misled into thinking the water is sufficiently deep to dive safely when it is not." 208 In Mulligan, Whealy J found that Mr Mulligan had observed others diving in the vicinity of the training wall and he had on previous occasions dived without mishap from approximately the same location. It was submitted by each plaintiff that each was misled into assuming that it was safe to dive when it was not. 209 In my opinion, the response to this submission is that the fact that Mr Mulligan on the one hand, and other people to Mr Vairy's observation on the other, had dived safely on other occasions did not neutralise or otherwise detract from the obvious risk of diving into water of unknown depth particularly where each was aware that the water depth was variable, that that variability related (at least in part) to the condition of the seabed on the one hand and the creek bed on the other, and that each well knew that it was dangerous to dive into water of variable depth. In such factual circumstances the reasonable response to the exercise of the defendants' duty of care did not require the erection of a warning sign or signs. 210 There was no finding by Bell J that Mr Vairy was specifically aware that the water surrounding the rock platform was of variable depth although her Honour did find that he was conscious of the risk of severe injury associated with diving due to the incident with his former wife's uncle. What was critical to her Honour was that, notwithstanding that he was unable to and did not observe the depth of the water, nonetheless he assumed it was safe to dive as a consequence of observing others doing so without mishap. Her Honour encapsulated this evidence in [169] of her judgment when she said: "The fact that it was common for people to dive from the rock platform was likely to lead others to consider that it is safe to do so. On some occasions it would be safe to do so and other occasions it would not be." In [167] her Honour had said this: "Nonetheless I am satisfied that diving from any position along the rock platform was dangerous in that it was attended by a real risk that the diver would strike the ocean floor and thereby suffer injury. That risk for a person diving was greater on some days than on others by reason of the movement of sand leading to significant variations in the depth of the ocean floor." 211 One could equally say that depending on a number of variable factors including the height from which one dived, the angle of dive, the height and weight of the diver, the state of the tide and the surge of the sea that at one moment of time it might be safe to dive from a particular location on the rock platform whereas on another it would not be. In my opinion, the point is that her Honour's recognition that it was dangerous to dive from any position along the rock platform, combined with Mr Vairy's consciousness of severe injury associated with diving as a consequence of his uncle-in-law's experience, gave emphasis to the basic proposition that the risk of injury of diving from the rock platform into water of unknown depth was both inherently dangerous and obvious. In these circumstances, the obviousness of the risk on the particular facts of the case is not neutralised by the knowledge of Mr Vairy that he had seen others dive from the rock platform without mishap and therefore assumed that it was safe for him to do so as well. In other words, given the obvious nature of the risk, he could not assume that there was no such risk merely because of his observation of the foolhardy actions of others. The adoption by him of the assumption that it was safe to dive because of his observations caused him to ignore a risk that was otherwise obvious. In my opinion, it would not be reasonable to impose upon Wyong Shire Council a duty to warn in these circumstances. 212 I have already referred to the shift in decisions of the High Court whereby persons ordinarily would be expected to exercise sufficient care for their own safety by perceiving and avoiding obvious dangers. It is true as pointed out in the joint judgment in Ghantous that allowance must be made for inadvertence. No question of inadvertence arose in either of the present cases. Inadvertence is different to the failure of a person to take reasonable care for his or her own safety. In the present cases, neither Mr Vairy nor Mr Mulligan took that care; otherwise they would have ensured that the depth of the water into which they each dived was sufficient to enable them to execute the manoeuvre safely. 213 I referred earlier to the variable depth of the waters in question as a consequence of naturally occurring phenomena. At one level of abstraction, it is the variable depth of the water caused by those phenomena that results in the risk of the water being of insufficient depth to enable a dive to be safely executed. However, it will be appreciated from what I have already written, that my preference is to define the risk not by reference to the variable depth of the water but to the unknown depth of the water in respect of which no assumption can be reasonably made by a person exercising reasonable care for his or her own safety that on a particular occasion and at a particular location that water will necessarily be deep enough to enable a dive to be safely undertaken. 214 Of course, it is not every risk presented by naturally occurring phenomena that is so obvious that it does not attract a duty to warn. This was acknowledged by the State during the course of argument in Mulligan where, for example, it was accepted that there was a duty to warn if, at a particular time of the year, a popular swimming spot was infested with blue ringed octopi. Another example given in the course of argument was a beach area where the flats (at low tide) contained areas of quicksand. The point, however, is that these are examples of risks presented by natural phenomena which are not obvious. It is for that reason that, in those cases, a duty to warn may in particular circumstances be imposed upon the relevant authority. 215 In the present cases however, the naturally occurring phenomena did not result in variations in the bed of the sea or tidal creek which were beyond what a reasonable person would expect in the circumstances with which he or she was confronted. Thus for instance, in Mulligan Whealy J (at [213]) found that "the proliferation of bedforms remained within normal and naturally occurring limits appropriate to a tidal estuary of the dimensions of Coffs Creek." Additional written submissions in the Mulligan appeal 216 On the final day of oral argument the Court granted leave allowing the parties to address, in written form, several matters raised during the course of that argument. In particular, leave was granted allowing Mr Mulligan's counsel the opportunity to: first, provide the Court with some documents said to be missing from the blue appeal books; secondly, to provide some evidentiary references to questions asked of counsel; and finally, to provide some further evidentiary references to material relating to the respondents' knowledge of the size of the bedforms in Coffs Creek. In each instance the respondents were granted leave to file written responses. 217 The document filed by Mr Mulligan's counsel included what were therein described as "supplementary written submissions". The respondents made the submissions in response to argument, in particular counsel for the State, that there was no evidence to support a finding that there were bedforms of 1 metre in water otherwise 2 metres in depth. The supplementary submissions addressed, and modified, an original written submission by Mr Mulligan which asserted: "Sixthly, the defendants knew (or ought to have known) that bedforms of up to approximately 1 metre could be found in a channel which was otherwise more than 2 metres in depth. That is an unusual hazard of which many swimmers would not be aware." The modified version read: "Sixthly, the defendants knew (or ought to have known) that bedforms of more than 1 metre could be found in a channel which was otherwise of 2 metres in depth. That is an unusual hazard of which many swimmers would not be aware (emphasis added)." 218 In essence the argument put forward in the supplementary written submission was based upon what, in the opinion of Mr Mulligan, ought to have followed from the primary judge's acceptance of the expert evidence of Mr Nielson, a coastal and geotechnical engineer retained on the plaintiff's behalf, who prepared a report following the undertaking of some inspections of the creek in late 1999. Mr Mulligan asserted that it followed from the acceptance of Mr Nielson's evidence that the defendants, through their knowledge of the creek, were required to erect a warning sign due to the occurrence of bedforms of more than 1 metre in water otherwise of 2 metres in depth. Due to the sign's absence, it now ought to be held that the defendants not only breached their respective duties of care, but also that they were causally responsible for Mr Mulligan's accident. This argument can be fleshed out more fully as follows. 219 The primary judge, by accepting the expert evidence of Mr Nielson in respect of the occurrence of bedforms in Coffs Creek, in essence accepted that on 10 November 1999 (a day upon which Mr Neilson inspected the creek), there were bedforms in the channel of up to 1 metre in water of a depth of 2 metres. Once this fact was accepted, it could be inferred that the primary judge also accepted that this condition would have previously occurred from time to time. Indeed, so it was contended, Mr Neilson's evidence indicated something to this effect. However, so the argument developed, the occurrence of such bedforms presented an unusual (or hidden) danger that would not be obvious to a swimmer. 220 Furthermore, the respondents knew, or ought to have known (at the least) of the occasional occurrence of such bedforms. Accordingly, since these bedforms presented a hidden danger, and the defendants knew of their existence, they had a duty to warn of the hidden dangers that these bedforms presented. Yet, no such warning was ever given by signage or otherwise. If, however, an appropriate warning had been given, then Mr Mulligan would not have dived into the creek. Thus, even if the bedform with which he collided was not one of 1 metre in height in 2 metres of water, the defendants were still causally responsible for the accident due to the fact that the Mr Mulligan would not have dived had the a warning been given. 221 The defendants' replies launched three attacks upon this submission. First, it was said that Mr Mulligan was ventilating a point raised neither at trial nor during oral argument on appeal. Second, it was claimed that the submission was wrong in fact. Third, it was submitted that the findings of the primary judge did not allow the submission to succeed. Each argument will be considered in turn. 222 It was submitted by the defendants that the trial was conducted by Mr Mulligan on the basis that their liability was said to stem from either of the following. First, that the installation of the rock training wall on the northern side of Coffs Creek caused an increase in the number and size of the bedforms such that a hidden danger was created which required warning. Second, that in any case the natural (i.e. the common or expected) occurrence of the bedforms in the creek created a danger which required warning. No argument was raised at trial along the lines of that presented in Mr Mulligan's supplementary written submissions. 223 Accordingly, it was submitted that at the trial not only was no special significance attached to Mr Nielson's evidence insofar as it may have spoken to the existence of 1 metre bedforms in 2 metres of water, but also no argument was mounted against the defendants as to the existence of bedforms. The supplementary submissions were therefore a wholly new line of attack. 224 Next, it was argued that there was no evidence, flowing from Mr Neilson or elsewhere, to the effect that there ever were bedforms of 1 metre in 2 metres of water. In this vein it was noted that Mr Nielson's evidence, in particular his report, nowhere suggests that such bedforms existed. 225 Finally, the point was made that since Mr Nielson's evidence does not establish that there were 1 metre bedforms in water 2 metres deep, then the primary judge, in accepting Mr Nielson's evidence, cannot be said to have found that such conditions ever existed. 226 In my opinion Mr Mulligan's supplementary submissions ought not to be accepted as they raise factual issues inconsistent with the means in which Mr Mulligan's case was conducted at first instance. Further, the submissions address matters not squarely raised in either Mr Mulligan's Notice of Appeal or Amended Notice of Appeal. Moreover, the arguments raise issues with respect to causation that were not argued on the appeal namely, whether a defendant can be causally responsible where there is a failure to warn in relation to one danger, but where the injury results from another danger about which there was no duty to warn. 227 In UTSA Pty Ltd (in liq) v Ultra Tune Australia Pty Ltd (1996) 21 ACSR 457, the Victorian Court of Appeal dealt with a situation where an appellant sought to advance oral arguments that differed both from those presented in the written submissions and those run in the court below. In essence what occurred was that on appeal and after the written submissions had been filed, a different counsel ran the appeal and developed and sought to run some fresh arguments concerning the plaintiff's case. Hayne JA, with whom Brooking and Phillips JJA agreed, refused to permit the new argument on essentially two bases. First, Hayne JA (at 459) identified the 'vice' associated with bringing new arguments to bear: "The real vice lies in the difficulties created for the opposite parties. They came to court expecting to meet one case. They were confronted by another, significantly different case." Second, his Honour pointed out (again at 459) that where one party has been given ample opportunity to present their case, but later wants to add to their case, it becomes unfair to the rights of other litigants to have the court's time delayed. (UTSA concerned an expedited hearing giving this second point more force in that case). 228 In the present case, not only is Mr Mulligan seeking to pursue an argument not run below, and not directly raised in the Amended Notice of Appeal, but also the argument, which was not the subject of the grant of leave, has been raised after the completion of oral argument. In my opinion, a party on appeal is not at liberty to raise, without leave, an argument not in issue in the court below, nor raised (or attempted to be raised) in oral argument when there existed the opportunity to do so. To raise such an argument after the rising of the court is, at least prima facie, unfair to the other parties to the litigation. 229 Further, in the present case, the factual issues raised by Mr Mulligan brings with it considerations that would make it difficult in a case involving complex expert evidence to make findings upon written documentation alone. That is, consideration would need to be given to such things as the length to height ratio of the bedforms. The proper forum for evidence of this nature would, no doubt, have been in the court below. To give but one example: the height/length characteristics of the bedforms may need careful scrutiny to properly address Mr Mulligan's argument. Thus, it may be unproblematic, and unworthy of warning, if a bedform of 1 metre in height gradually, and ramp-like, builds up to this height over a length of several metres. The point here is that it would do a great disservice to the defendants to have these factual issues determined both post-trial and post-oral argument. For these reasons, the supplementary submissions, insofar as they stray from the leave granted, ought not to be considered. 230 Irrespective of the above, there is, in my opinion, no evidence to substantiate Mr Mulligan's assertion that Mr Nielson witnessed bedforms of 1 metre in of 2 metres in depth so that the primary judge, in accepting Mr Nielson's evidence, accepted this to be the case. 231 In his report, when describing the conditions that he witnessed on 10 November 1999, Mr Nielson makes the following observation: "[T]he bed of the creek portrayed relatively large undulations, particularly on the southern side, with bed level variations reaching values in excess of 1m along a line extending downstream equidistant some 5m to 10m (approximately) from the southern bank, at some locations the depth of water was in the order of 2m (overhead) whereas at other locations it was as little as 0.5m (knee deep)." 232 It is this observation that founds Mr Mulligan's claim that Mr Nielson witnessed (and the primary judge accepted) the presence of bedforms of 1 metre in water that was 2 metres in depth. However, the above passage does not stand for that proposition. Mr Nielson merely records that he saw bedforms of over 1 metre in depth. He does not state the depth of the water in which these bedforms were located. He certainly does not state that they were in water that was 2 metres in depth. Given that the depth of water in the creek fluctuated with the tide, it may be that at times the water in the creek was 2 metres deep. Rather, as well as recalling that he observed bedforms of over 1 metre in depth, he also observes that he witnessed water that was over 2 metres in depth but without relating that depth to whether or not there were 1 metre bedforms, or indeed any bedforms, in that location. Accordingly, Mr Mulligan's submission seems factually flawed. Further, and in any event, it is also apparent that Mr Nielson is doing no more than recounting his observations. He is not reporting a series of measurements that he conducted in the creek. That is, he is recalling what he merely observed as opposed to what he scientifically ascertained. 233 Finally, the comments of the primary judge with respect to the expert evidence, in particular that of Mr Nielson, do not in my opinion lead to any of the conclusions now advanced by Mr Mulligan. In particular, the primary judge in considering that evidence makes clear (at [212]) that its importance lies in its ability to inform the court of the likely conditions in the creek at the time of the accident. In this respect his Honour said: "[I]t was and is my view that, generally speaking, the expert evidence is very important in reaching an understanding of the likely conditions in the creek bed on the day of the accident." 234 Accordingly, it was in this respect that the primary judge (at [208]) accepted the evidence of Mr Nielson. That is nowhere did he accept that there were bedforms of 1 metre in water of 2 metres (for the reasons given above). Further, his Honour expressed no opinion as to whether the bedforms reported by Mr Nielson were unusual; nor to their frequency of occurrence in the past. 235 Moreover, insofar as the expert evidence spoke to the conditions in the creek on the day of the accident, the primary judge (at [210]) found that the bedforms would not have been as large as those encountered by Mr Nielson. He said: "[I]t is more probable than not that bedforms in the creek area where the plaintiff was diving were not as large as those encountered by Mr Nielson. In all probability they would have been less than 0.5 metres and were unlikely to have been as prevalent as they had been on earlier occasions." 236 In one sense, this statement does not impact upon Mr Mulligan's submissions: he is not concerned with the conditions at the accident site. Rather he is asserting that if anywhere in the creek there had in the past been bedforms of 1 metre in water 2 of metres depth, then the defendants had a duty to erect a warning sign. However, what [210] does show (which does affect the appellant's submissions) is that the primary judge in this passage of the judgment was determining the conditions on the day of the accident and made no findings with respect to the past general conditions of the creek. No doubt he took this course as the argument now advanced formed no part of the plaintiff's case at trial. 237 For these additional reasons, Mr Mulligan's supplementary submissions, insofar as they stray from the leave granted, ought to be rejected. 238 It thus follows that, in my opinion, none of the defendants in either case was in breach of its duty of care to the respective plaintiffs. Accordingly, the appeal in Vairy should be allowed and that in Mulligan dismissed. 239 The foregoing conclusion is sufficient to dispose of both appeals. It is therefore not strictly necessary for me to deal with the other issues that were raised by the defendants in each appeal. However, as they were fully argued, I shall express my views on the arguments raised. The additional issues raised in Vairy 240 Apart from the issue of breach of its duty of care, Wyong challenged Bell J's findings on the issue of causation and contributory negligence. Causation 241 The issue here is whether, had Wyong erected signs warning of the danger of diving from the rock platform, Mr Vairy would have heeded the warning and not dived. Mr Vairy said, and her Honour accepted, that had he seen a sign in the vicinity of the rock platform before he dived either on the day of his accident or in preceding days or weeks, and which said "Diving Prohibited" or contained a pictogram symbol of a person diving with a red line through it indicating that diving was not allowed, he would not have dived from the rock platform. 242 Her Honour acknowledged that the question of causation was to be determined subjectively: Chappel v Hart (1998) 195 CLR 232 at 247. She also acknowledged the following observations of McHugh J in that case (at 246): "Human nature being what it is, most plaintiffs will genuinely believe that, if he or she had been given an option that would or might have avoided the injury, the option would have been taken. In determining the reliability of the plaintiff's evidence in jurisdictions where the subjective test operates, therefore, demeanour can play little part in accepting the plaintiff's evidence. But given that most plaintiffs will genuinely believe that they would have taken another option, if presented to them, the reliability of their evidence can only be determined by reference to objective factors, particularly the attitude and conduct of the plaintiff at or about the time when the breach of duty occurred". 243 The primary judge found that Mr Vairy was not a person in the habit of disobeying warning signs: nor was he a person inclined to take risks associated with his participation in sports such snow and water skiing. In accordance with the considerations to which McHugh J referred in Chappel, she then considered whether to accept Mr Vairy's evidence by reference to other objective evidence that bore upon his attitude and conduct around the time of the accident. 244 Her Honour then referred to the evidence of witnesses who attested to Mr Vairy's responsible attitude and conduct with respect to his participation in water skiing and supervision of children. She considered that had Wyong erected warning signs, it was reasonable to assume that a number of people would have been deterred from diving from the rock platform and that Mr Vairy would have observed fewer people jumping and diving therefrom on the day of his accident. However, it is clear that her Honour considered that some people would ignore the warnings. She then noted the diving accident and sequelae thereof to Mr Vairy's Uncle Chris. She concluded (at [209]) that he was aware of that accident which "made him conscious of the risk of severe injury associated with diving" 245 The primary judge then concluded that she did not consider that Mr Vairy was so intent on diving off the rock platform that he was unlikely to have been deterred by a warning sign. She particularly considered it unlikely that he would have dived from the rock platform contrary to the terms of any such warning sign in the presence of his 11 year old niece. She expressed her conclusion in these terms (at [212]): "In the event that signs warning of the danger of diving (by reason of the variable depth of the water or by reason of shallow water) had been erected in the vicinity of the rock platform I am satisfied that it is likely that the plaintiff would not have dived from it. The plaintiff was particularly conscious of the risk of spinal injury associated with diving because of Uncle Chris' accident. A warning that served to bring the risk of diving from the rock platform to his attention I think would probably have led him not to run that risk." 246 As well as the passage from the judgement of McHugh J in Chappel to which the primary judge referred, Wyong also relies upon the following passage from the judgment of Gleeson CJ in Rosenberg at 441 [16]: "Recent judgments of this Court have drawn attention to the danger of a failure, after the event, to take account of a context, before or at the time of the event, in which a contingency was to be evaluated. This danger may be of particular significance where the alleged breach of duty of care is a failure to warn about the possible risks associated with a course of action, where there were, at the time, strong reasons in favour of pursuing the course of action." 247 Wyong submits that in the present case there were strong reasons in favour of Mr Vairy pursing his intention to dive from the rock platform notwithstanding the existence of a sign warning of the danger of so doing. It was submitted that it would be unrealistic to infer that, had there been such a sign, Mr Vairy would not have made the same assumption as to safety on the day based upon his previous observations and those he had made on the day of the incident. However, as I have already observed, the primary judge considered that there would have been fewer people on any given day to be seen jumping and diving from the rock platform had such a sign been erected. This may well have altered the assumption upon the basis of which Mr Vairy proceeded to dive in the present case. 248 It is true, as Wyong submits, that signs are commonly ignored and disobeyed in circumstances where people have made their own assessments and decisions based on their own experiences or observations. Equally, I can accept that it is inappropriate to attribute a "talismanic effect" to such signs, as Bryson J observed in Lodge at 459 [35]. 249 Although it was submitted that the primary judge's conclusion that Mr Vairy would have heeded an appropriately worded warning sign and not dived from the rock platform because he had, on some occasions, disobeyed signs and warnings, nevertheless there was ample evidence from which it was open to her Honour, as she did, to accept that he was not so intent on diving off the rock platform that he was unlikely to have been deterred from so doing by a warning sign. In my opinion her Honour's finding was justified by the evidence and supported by cogent reasons. As no error has been demonstrated, Wyong's challenge to her Honour's finding on causation should be rejected. Contributory negligence 250 Wyong had submitted before the primary judge that Mr Vairy's own negligence contributed to his loss as a consequence whereof any damages awarded to him should be reduced by between 70%-80% pursuant to s 9 of the Law Reform (Miscellaneous Provisions) Act 1965. Guided by the principles enunciated by the High Court in Podrebersek v Australian Iron & Steel Pty Limited (1985) 59 ALJR 492 at 493-494, her Honour concluded that Mr Vairy had failed to take reasonable care for his own safety. She expressed her conclusions in the following paragraphs of her judgment: "221. In this case I am satisfied that the plaintiff who was a mature adult did not make any independent assessment of the depth of the water before diving. His only assessment depended upon the inferences that he drew from seeing other persons jumping and diving from the platform in the minutes before he dived and his observations of people jumping and diving from the rock platform over the previous four years. 222. It seems to me that the plaintiff failed to take reasonable care for his own safety by not making any independent assessment of the depth of the water before he dived. The fact that he had frequently seen people diving on other occasions and that he saw some persons diving from it on this day I do not consider to relieve him of responsibility, as a person taking reasonable care for his own safety, for ensuring that the depth of the water was sufficient to make diving on this occasions safe for a person of his height." 251 However, her Honour rejected Wyong's submissions that Mr Vairy's culpability as between it and him was by far the greater and that the proximate and significant cause of his injury was his own carelessness. She concluded that the appropriate reduction in any award of damages on account of Mr Vairy's own negligence to be one of 25%. 252 Wyong submits that her Honour erred in so finding. It submitted that the proximate cause of Mr Vairy's injuries was his own decision to dive from the rock platform, not knowing how deep the water was and not having formed any view as to its depth and, therefore, not having formed a view or turned his mind as to how safe it would be for him to dive. Mr Vairy had conceded that in diving into the water without being able to see the bottom "he took the risk" that the water was deep enough. As her Honour observed on the issue of causation, he was well aware of the risk of severe injury associated with diving as a consequence of the experience of his Uncle Chris. Accordingly, it was submitted that he was well armed with knowledge of the grave consequences that could befall those who entered waters of unknown depth without first investigating the condition of the water into which he intended to dive. 253 The relevant principles with respect to the interference by this Court in a primary judge's apportionment of responsibility were recently restated in Berryman v Joslyn; Wentworth Shire Council v Joslyn [2004] NSWCA 121 at [20]-[25]. Those passages emphasise that findings of a trial judge with respect to apportionment of responsibility are not likely to be disturbed on appeal. However, if error is shown, whether of law or fact, an appellate court is authorised to intervene. Furthermore, if it can be inferred that upon the facts the result reached by the trial judge is unreasonable or plainly unjust in the sense in which those expressions are used in House v The King, then intervention is justified. 254 In the present case the primary judge found that Mr Vairy did not observe the ocean floor although he could have seen it had he looked. She further found that he did not take any steps to assess the depth of the water adjacent to the dive location before he dived. He just assumed that it was safe to dive because he had seen people on that day diving and jumping from the rock platform as well as on previous occasions. On the other hand, he was well aware of the accident that had befallen his Uncle Chris and that in diving into the water without being able to see the bottom, he took the risk that the water was deep enough for him to do so safely. Accordingly, it is clear that he failed to exercise reasonable care for his own safety to a high degree. What he did was simply foolhardy. 255 In my opinion, the primary judge failed to give appropriate weight to these factors. To find that Mr Vairy was only 25% responsible for his loss was, with respect, unreasonable in the circumstances. Accordingly, error has been shown. 256 It thus becomes necessary to reassess the extent of Mr Vairy's contributory negligence. That exercise requires consideration of what is "just and equitable" between the parties. In accordance with the principles stated by the High Court in Podrebersek, the apportionment exercise between Mr Vairy and Wyong of their respective share in the responsibility for the former party's loss involves a comparison both of culpability and of the relevant importance of the acts of the parties in causing his injuries. 257 In my opinion, taking into account all the circumstances, including the factors to which I have referred, I would consider that it would be just and equitable to reduce Mr Vairy's verdict against Wyong (if he be otherwise entitled to one) by 55% as a consequence of his contributory negligence. The additional issues in Mulligan Did Coffs Harbour owe Mr Mulligan a duty of care? 258 As I have already observed ([48]), the primary judge held that Coffs Harbour owed Mr Mulligan a duty to take reasonable care to avoid foreseeable risks of injury to persons swimming in the creek whether they entered it from the northern reserve or the Jetty Reserve. It was not contested that Coffs Harbour owed such a duty in respect of persons entering the creek from the northern reserve or that that duty extended to the whole of the creek from one side to the other. However, it was submitted that his Honour had erred in extending the duty of care to those persons who entered the creek from the Jetty Reserve or southern bank, which was an area in respect of which the Council had neither care, control nor management. 259 It was contended that as Coffs Harbour was not the owner, occupier nor manager of the southern bank of the creek, it had no power to take any steps to prevent injury to Mr Mulligan and, in particular, it had no power to erect warning signs on that bank or otherwise within the Jetty Reserve. 260 The primary judge sought to apply, by analogy, the decision of the High Court in Nagle in which it had been held that the defendant owed a duty of care to the plaintiff upon the basis that it had promoted the Basin area for recreational purposes and had actively encouraged the public to use it for that purpose including for swimming and diving. His Honour found that Coffs Harbour had promoted the area of the creek generally as a venue for swimming and had in fact encouraged the public to use the creek between the Orlando Street bridge and the ocean for swimming and related recreational purposes. Furthermore, it had provided car park facilities on both the northern and southern side of the creek, had contributed to the cost and construction of the footpath/cycleway leading from the Orlando Street Bridge through the Jetty Reserve and had erected signs on that reserve close to the man-made paths leading to the southern bank of the creek and to Park Beach warning the public that the beach area was unpatrolled. His Honour's finding was as follows (at [251]): "There can be no doubt that the Council promoted and encouraged the general area of the Jetty, Park Beach and the creek area east of the Orlando Street bridge as a significant recreation area for tourists and locals. It would be naive in the extreme to find that such encouragement did not exist in the present case. It is true that the type of encouragement differed in a number of respects from that found in Nagle . But I am satisfied that this particular location was at the very centre of the recreational facilities that were themselves central to the main tourist attraction of Coffs Harbour." 261 Coffs Harbour submitted that it did not have any statutory responsibility for the care, control and management of Coffs Creek or of the Jetty Reserve in any of its capacities. Nor had it assumed that responsibility. As Mr Mulligan had entered Coffs Creek from land for which the Trust had the care, control and management, it was the relevant "statutory occupier" of that land. Furthermore, unlike the position of the Rottnest Island Authority in Nagle, Coffs Harbour had not actively encouraged the use of the Jetty Reserve for the purpose of gaining access to the creek. Its general promotion and encouragement of tourism in the area was not, so it was contended, sufficiently direct to enable the decision in Nagle to be applied to the present case by way of analogy. It was submitted that although it may be that Coffs Harbour had facilitated access to the Jetty Reserve by the construction of the concrete pathway/cycleway, that infrastructure had served the dual purpose of providing amenities for people who visited the area and protecting of the environment but did not constitute "encouragement" for members of the public to stray from the pathway and enter the creek from the southern bank. In other words, there was no encouragement by Coffs Harbour to members of the public to deviate from the pathway for the purpose of swimming in the creek. 262 As I have observed, the primary judge found that not only had Coffs Harbour provided pull-over for motor vehicles on the eastern side of Orlando Street (to the south of the creek) and participated in the construction of the concrete pathway/cycleway that ran from the Orlando Street bridge across the Jetty Reserve and then along Park Beach, it had also erected signage, including warning signs, on the Jetty Reserve. Furthermore, the evidence established that Coffs Harbour not only had the care, control and management of the area of the creek to the west of the Orlando Street bridge but also of the area of the pathway where it extended beneath the railway bridge pursuant to the licence granted to it by the relevant railway authority. Furthermore, Coffs Harbour had erected signage between the two bridges. 263 Accordingly, if Coffs Harbour was otherwise under a duty to take reasonable care by the erection of warning signs, whether or not it was empowered to erect such signs upon the Jetty Reserve, it was certainly empowered to erect such signs at any point up to the eastern boundary of the licensed area beneath the railway bridge. Given that Mr Mulligan utilised the concrete pathway to that point for the purpose of gaining access to the southern bank of the creek, at the very least Coffs Harbour's duty of care extended up to that point if not beyond. A warning sign erected next to the pathway at the eastern boundary of the licensed area beneath the railway bridge would have warned Mr Mulligan of the dangers associated with diving in the creek if he deviated from the pathway on to the southern beach of the creek at a point a few metres to the east of that boundary. 264 Whether Coffs Harbour's duty of care extended past the eastern boundary of the licensed area may be more problematic. Even if it did not have the power to erect signage within the Jetty Reserve, it clearly could do so with the consent of the Trust and one can infer that that consent was forthcoming in respect of the signs which the Council did erect along the pathway warning that the beach was unpatrolled. Although it is unnecessary to finally decide the point, I consider that in all probability the better view is that the primary judge was correct in extending Coffs Harbour's duty of care to the southern bank of the creek. 265 Accordingly, in my opinion, Coffs Harbour did owe Mr Mulligan a general duty of care as a consequence whereof its challenge to his Honour's finding in that respect fails. Did the State interests owe Mr Mulligan a duty of care? 266 The primary judge also held that the State was under a general duty to take reasonable care to avoid foreseeable risks of injury to persons lawfully swimming in the creek itself in the area where Mr Mulligan was injured. The factual basis of this finding was the activities of the Department of Public Works (the Department) in relation to the creek bed extended to the assumption of an active management role in relation to it, albeit that they were shared with Coffs Harbour. That is, the State, mainly through the Department, had actively involved itself, often in company with Coffs Harbour, with the creek. This activity included the protection and development of the creek's natural environment and assistance, including financial, with the ongoing development of the creek as a recreational area. This interest and activity demonstrated that the State, along with Coffs Harbour, perceived the area as a principal part of Coffs Harbour's tourist appeal. 267 The primary judge also held that the Trust owed a general duty of care to those entering the Jetty Reserve. The land under its care, control and management extended to the southern mean high water mark of the creek. His Honour found that the Jetty Reserve was a most attractive area and one likely to be well used by a very significant number of people. He considered that the concrete pathway/cycleway was a facility in its own right which ran through the entire reserve and was an important feature of the enhancement of the recreational facilities provided jointly by the creek, the swimming areas in the creek, the reserves, Park Beach, the Jetty, the Harbour and Mutton Bird Island. As he found (at [258]): "Again, it would be contrary to common sense to suggest that the Reserve and the pathway, given the adjacent access paths to the creek, did not offer the most obvious encouragement to swim in the creek in that location." 268 The State submitted that, as far as the bed of the creek was concerned, it did no more than hold the land and that it had a passive role with respect thereto. Although it had statutory power to manage the land as Crown land, it did not take steps to encourage or promote its public use. So far as the creek bed was concerned, it "was merely there". 269 A similar submission was put with respect to the Jetty Reserve. It was submitted that the Trust did nothing to promote or encourage its use and although it had the care, control and management of the land constituted by the Reserve, that of itself was insufficient to give rise to a duty of care: Romeo at 440 [15]. 270 It was also submitted that no factual circumstance had been demonstrated creating a relationship between the State and/or the Trust on the one hand and Mr Mulligan on the other which would ground a duty of care. It was thus submitted that the findings of the primary judge in [62] of his judgment required the conclusion that it was Coffs Harbour, rather than the State interests, that had assumed responsibility for the creek and its southern bank so far as the use of those areas as a recreational facility were concerned. Accordingly, it was contended that the State and the Trust merely acted as consent authorities, advisors, funds providers and contractor for works managed by Coffs Harbour. There was therefore no relevant relationship between the State interests and Mr Mulligan to found a duty of care. 271 A finding of an assumption of responsibility in respect of the areas in question on the part of Coffs Harbour does not necessarily negative a similar assumption of responsibility on the part of the State interests. In [256] and [257] of his judgment the primary judge concluded, as I have already noted, that the State through the Department had adopted an active management role in relation to the creek and its surrounds. It was submitted that his Honour's conclusions were in general and non-specific terms and insufficient to give rise to a relevant relationship between the State interests and Mr Mulligan as an entrant as of right to the area promoted as a tourist facility by Coffs Harbour. 272 In my opinion, the State interests' submissions should be rejected. At the end of the day, they did not challenge the primary judge's findings of fact as to the role of the Department in relation to the management of the creek and the Jetty Reserve. In addition, the relationship between the State interests and Mr Mulligan was sufficiently close to give rise to a generalised duty of care owed by the State and the Trust to Mr Mulligan and his Honour was correct in so finding. 273 I should add that the State interests submitted that the risk of injury to Mr Mulligan was not foreseeable but was far-fetched or fanciful and that this fact negated the existence of any duty of care. It was submitted that it was necessary for Mr Mulligan to establish and secure a finding of fact that a reasonable person in the position of the State ought to have foreseen that a failure to warn of variable depths in the creek might cause injury to Mr Mulligan or a person in his position. It was contended that no such finding was made. In particular, it was submitted that in his consideration of the breach issue, the primary judge found to the contrary. 274 However, the primary judge did make such a finding. At [288] he said this: "Despite Mr Maconachie QC and Mr McCulloch's strong assertions to the contrary, I am satisfied that the danger of a person such as the plaintiff sustaining severe injury as the result of diving in the creek was reasonably foreseeable. It was neither far-fetched nor fanciful to consider that a person swimming in this area of the creek might sustain very serious injury by coming into contact with the creek bed, sand dunes or the creek bed or an object or objects on the creek bed." 275 In my view, this finding was clearly intended by his Honour to extend both to both the State interests and Coffs Harbour. Accordingly, in my opinion his Honour was correct in finding that both the State and the Trust owed Mr Mulligan a generalised duty of care. Causation 276 Both Coffs Harbour and the State interests challenged the primary judge's finding on causation. Mr Mulligan's obligation to establish causation was described by the primary judge in the following terms (at [312]): "In practical terms, this means that the obligation fell on the present plaintiff to prove on the balance of probabilities that if the missing sign or signs had been erected, the plaintiff would not have suffered his injuries. To prove this, the plaintiff needed to show that such a sign or signs would probably have been seen by him and taken into account by him with the probable consequence that he would not have dived in the creek as his subsequently did." 277 His Honour then referred to the well-known observations of McHugh J in Chappel at 246 to which Bell J had also referred in Vairy. He then referred to the evidence in chief of Mr Mulligan that if a sign warning him in relation to diving in the creek had been displayed, that is, a sign warning him against diving in the creek because of its variable depth, he would have obeyed it and not dived into the water as he did. This evidence was given in the context of a question that related to the manner in which he approached the southern bank of the creek. 278 The primary judge considered that there were two major matters for consideration in relation to the issue of causation. The first was whether there were factors that demonstrated the reliability of Mr Mulligan's evidence, particularly those factors bearing upon his attitude and conduct at or about the time he was swimming and diving in the creek. The second related to the following exchange that took place during his cross-examination: "Q. You would agree, would you not, that any signs which related to the creek and which were erected at any point adjacent to the railway bridge, or where the worn path was that you took, would have meant nothing to you in those circumstances because it wasn't part of your intention at that stage to swim in the creek? A. That is correct." 279 However, in re-examination he was asked the following: "Q. What would you have done in the circumstances in which I outlined the point where you made the decision to go into the creek rather than the sea? What would you have done if there had been a sign there warning you against diving and advising you of the variable depth of the water? A. Well I would not have dived into the water." 280 His Honour accepted the evidence given by Mr Mulligan as expressing his honest belief at the time he gave his evidence that he would not have dived had there been an appropriate sign or signs warning him of the relevant danger. He considered that Mr Mulligan was a sensible young man who generally speaking behaved in a responsible and careful manner. This was evidenced, so he found, by the fact that Mr Mulligan took a measure of care in relation to assessing the depth of the water into which he was about to dive and which reflected a tacit realisation of the need to take some care in relation to the angle of his dive. 281 Furthermore, the primary judge found that Mr Mulligan was a train driver who, by his training, was accustomed to be aware of and obey signs. As he was a stranger to Australia and its conditions, his Honour accepted that he was more likely to heed a sign dealing with specific local conditions. 282 Although a number of submissions were made to the contrary, his Honour rejected them. He thus concluded on the first issue (at [324]) that "the plaintiff's general conduct, his general standing and behaviour in the community and his specific conduct on the day in question leads me to believe that he was the sort of person who would have been most likely to have obeyed a sign which warned him of the dangers of diving in the creek." 283 The primary judge then turned to the question and answer in cross-examination which I have referred to in [278]. He noted that the question itself related to a hypothetical situation as there was, in fact, no sign adjacent to the railway bridge or any sign at any point along the well-worn path. His conclusion with respect to this issue was as follows: "In my opinion, giving the relevant evidence such weight as it is worth, the fact remains that, if the plaintiff, within a very short space of time, had come to a conclusion that he wished to swim in the creek rather than the ocean, the probabilities are that he would have recalled a sign near the railway bridge which warned him of the danger of diving in the creek. The decision (or at least the possibility of) a swim in the creek occurred to the plaintiff within a few moments of walking past the bridge. Logically it must be correct to say, as the plaintiff did, that the sign would have meant "nothing" to him at the time he stood at the bridge but it may well have struck a response a few moments later when he contemplated a swim in the creek. This is even more likely to have been the situation had there been a sign on the well worn path itself or on some part of the southern bank of the creek where the plaintiff and Miss Brady stood at the time the relevant decision was made. This was the thrust of the answer given in re-examination." 284 Accordingly, his Honour was satisfied that Mr Mulligan would, more probably than not, have heeded any appropriate signs and refrained from diving in the manner he did. 285 Coffs Harbour submitted that the effect of Mr Mulligan's answer in cross-examination recorded in [278] above destroyed the evidence that he gave in chief and in re-examination. In particular, it was submitted that even if he had seen the sign referred to by the cross-examiner, it would not have continued to operate on his mind more than half an hour later and would not have been operating on his mind 1½ hours later when he made his final dive which resulted in his injuries. As I see it, the difficulty with this proposition is that upon the primary judge's findings, Mr Mulligan would not have dived at all: in fact, he would have recalled the sign within the very short space of time after he decided to swim in the creek rather than the ocean. 286 It was next submitted that as he had formed the intention not to dive in the shallow part of the creek near the railway bridge but to dive further to the east where he thought the water was sufficiently deep to enable him to dive safely, the existence of any sign would no longer have continued to operate upon his mind. In my opinion, the answer to this argument is the same as that to the previous submission, namely, that when Mr Mulligan decided to swim in the creek rather than the ocean, he would have recalled the sign and would not have dived either in the shallow section of the creek where he first swam or in the deeper section where he later swam. 287 The State interests next submitted that the primary judge asked himself the wrong question when asking whether there were factors which demonstrated the reliability of Mr Mulligan's evidence which he described as his "subjective protestation", a phrase coined by Kirby J in Romeo at 482 [134] cited by his Honour in [314]. However, the manner in which his Honour posed the question to himself was consistent with the remarks of McHugh J in Chappel at 246, which he had cited in [313]. Further, I do not regard the question that his Honour addressed to himself as being inconsistent with the statement of Kirby J in Romeo that it was one for objective assessment rather than subjective protestations after the event. The manner in which his Honour dealt with this issue makes it clear, in my opinion, that he was seeking out evidence which, objectively, would enable him to conclude (as he did) that Mr Mulligan would most likely have obeyed a sign which warned him of the dangers of diving into the creek. 288 The State interests then submitted that his Honour's finding that Mr Mulligan acted with caution and circumspection when he was diving in the creek was unjustified. Reliance was placed upon a number of factual matters which established that Mr Mulligan was aware that the creek was of variable depth; that the water was cloudy and therefore he lacked visibility, and that he "did not know whether it was four feet or fourteen feet deep". These were the same matters that were relied upon by the State interests to establish the obviousness of the risk as discussed above. 289 However, I see no basis upon which this Court should interfere with his Honour's finding in [319] that, on the afternoon in question, Mr Mulligan behaved in a responsible and careful manner in that he "took a measure of care in relation to assessing the depth of the water into which he was about to dive. His method of diving into the water was moderate ('a shallow dive'). It reflected a tacit realisation of the need to take some care in relation to the angle of the dive." Accordingly, I would reject this aspect of the State's argument. 290 The State also attacked the primary judge's finding at [329] to the effect that Mr Mulligan would have recalled a sign if, within a very short space of time, he had decided to swim in the creek rather than the ocean. The State argued that this finding suggested that Mr Mulligan, upon seeing such a sign (had one been erected), would have determined then and there not to dive into the creek. However, the evidence revealed that Mr Mulligan did not turn his mind to diving for another half and hour: at this point he merely decided to swim in the creek and not the ocean. Accordingly, his Honour was said to have erred by telescoping or foreshortening the timeframe between when Mr Mulligan might have seen a warning sign and the time at which he determined to dive. 291 In my opinion, this challenge to his Honour's findings should be rejected. There is no reason to believe that by the time Mr Mulligan decided to dive he would not have recalled a warning sign that directed his mind to the safety of so doing. I see no reason why it was not open to his Honour to have considered that such a sign would have struck a response with him at the time he contemplated swimming in the creek rather than the ocean and that its impact upon his thinking at that point would have, there and then, persuaded him not to include diving in his proposed aquatic activities. 292 Finally, the State interests submitted that the primary judge overlooked, or did not adequately deal with, a submission made at trial that the chain of causation was broken by Mr Mulligan's deliberate and informed act of diving when he did with the knowledge then possessed by him. It was submitted that Mr Mulligan knew what the defendants were obliged to warn him about; that the creek was of variable depth; that he was not coerced into entering the water in the manner in which he did and that he chose freely to dive into cloudy water of unknown depth. 293 This argument is no different from the defendant's submission that Mr Mulligan voluntarily accepted the risk, which the primary judge rejected. His Honour did so upon the basis that the defendants had not established that Mr Mulligan was fully aware of the risk or that he had a complete understanding of its nature and extent. As will appear hereafter, in my opinion, the defendant's challenge to his Honour's finding with respect to the defence of voluntary assumption of risk should be rejected. On that basis Mr Mulligan's conduct was not relevantly free and informed. 294 Furthermore, the principle requires that the relevant act or omission be intended to exploit the situation created by the defendant's negligence. It is this aspect of the principle that confines it to subsequent intervening events. Thus, in Nominal Defendant v Gardikiotis (1996) 186 CLR 49 at 55, McHugh J said: "Under the common law theory of common sense causation, a free, informed and voluntary act of the plaintiff or a third party, which builds on a situation resulting from the defendant's tort and causes loss or damage to the plaintiff, negatives any causal connection between the tort and the loss of damage." (emphasis added) 295 In my opinion, the State interests have taken this passage out of context and have overlooked the fact that whether the relevant act be by the plaintiff or a third party, it must build "on a situation resulting from the defendant's tort". That principle, as related to subsequent intervening events, is recognised by Professor Luntz, Assessment of Damages for Personal Injury and Death, 4th Ed, pp159-163 esp. at 160 [2.1.11]. 296 The submission of the State interests on this issue thus overlooks the fact that the principle contended for is concerned with an act or omission (be it of the plaintiff or the third party) subsequent to the defendant's act or omission and which severs the chain of causation between that act or omission and the plaintiff's injury. However, in the present case, the diving activities of Mr Mulligan were not intended by him to exploit any situation created by the defendants. In my opinion, the State's submission should be rejected. Voluntary assumption of risk 297 Both Coffs Harbour and the State interests submitted that the defence of voluntary assumption of risk had been established. In considering this issue, the primary judge commenced his discussion by reference to the decisions of the High Court in Insurance Commissioner v Joyce (1948) 77 CLR 39 and Roggenkamp v Bennett (1950) 80 CLR 292 at 300. After referring to the decision of Studdert J in Beck v State of New South Wales [2001] NSWSC 278 at [61], his Honour cited a passaged from Halsburys Law of Australia (1994) Vol. 19 at 300 - 140 which included the following: "it is a defence to an action in negligence if the defendant can prove that the plaintiff knew of and voluntarily accepted the risk of suffering injury or damage as a result of the defendant's negligence . … … The question whether the plaintiff's acceptance of the risk was voluntary is generally a question of fact and the answer to it may be inferred from his or her conduct in the circumstances. A person cannot be taken to have voluntarily assumed the risk of negligence on the part of another merely by engaging in a sport or pastime…" (emphasis added) 298 The primary judge then quoted extensively from the judgment of Walsh JA, with whom Jacobs and Holmes JJA agreed, in Sara v Government Insurance Office of New South Wales (1969) 89 WN (Pt 1) (NSW) 203 at 207 where his Honour stated the defence in terms of a plaintiff, with sufficient knowledge, voluntarily accepting "the risk of physical injury". 299 His Honour then referred to the unreported decision of this Court in Hadland v Council of the City of Blacktown, 21 May 1997 with particular reference to the judgment of Clarke A-JA that suggested that, in order to sustain the defence, the defendant must prove that the plaintiff, in accepting the risk of injury created by the danger, absolved the defendant from any responsibility for her resultant injury. Clarke A-JA considered (at p.6) that it was "only where the inference is drawn that the plaintiff consented to run the risk at his or her own expense, in the sense that he or she could not sue if injured, that the defence will prevail." 300 Handley JA agreed with the orders proposed by Clarke A-JA but expressed a reservation in relation to the passage cited above. His Honour said: "Where the relationship between the parties is gratuitous, the existing authority in this Court appears to establish that the defence is made out 'if the plaintiff, with sufficient knowledge, voluntarily accepts the risk of physical injury'. See Sara v Government Insurance Office (1969) 89 WN (Pt 1) (NSW) 203 at 207 per Walsh JA speaking with the concurrence of Jacobs and Holmes JJA." 301 The primary judge considered that it was unnecessary for him to resolve the differences between Clarke A-JA and Handley JA as expressed in Hadland for the defendants had failed to make out the defence on either test. He considered that the facts did not establish that Mr Mulligan "with sufficient knowledge voluntarily accepted the risk of physical injury". 302 The primary judge then set out (at [340]) five points arising out of Mr Mulligan's evidence as to the sequence of events leading to his accident. The fifth point was his finding that while Mr Mulligan accepted in general terms the risk associated with diving in the creek, he did not regard his precise activities in the creek as dangerous. For this finding he accepted the following answers given by Mr Mulligan in the exchange below: "Q. And you knew that the risks were potentially serious? A. From experience, I have done it so many other times before and in different places in the sea that I didn't see a danger in it at the time, no. Q. What you mean by that, is that you have never been injured before and you didn't see why it would occur on this occasion, is that what you are saying? A. Yes." 303 His Honour concluded that the defendants had not made out the defence of voluntary assumption of risk. His reasons were as follows (at [342]): "…Accepting as I have done the truthfulness and reliability of the plaintiff's evidence as to his state of mind and the sequence of events involved in the circumstances leading up to his injury, it is clear that the defendants have not proved that the plaintiff was fully aware of the risk; nor have they proved that the plaintiff had a complete understanding of the nature and extent of the risk. The plaintiff must be taken to have understood that, in general terms there was an inherent risk in swimming and diving in a creek of variable depth, especially a creek where the current was running freely and there was no visibility of what lay beneath the surface. But it is clear he misjudged the situation on his last dive. Further, the defendants have simply failed to prove on the facts of this case that the plaintiff voluntarily accepted the risk. I do not consider that the plaintiff, prior to the accident, fully appreciated in the sense relevant for the establishment of this defence the precise danger he faced. The assumption he made (wrongly) was that it was safe to repeat his dive where he did and in the manner he did. Nor did he, with a full appreciation of that risk, voluntarily accept the risk of physical injury." 304 The State interests submitted the primary judge had misdirected himself in point of law by his adoption of the passage from Halsbury which I have recorded in [285] above in that the defence does not require an assumption of the risk of negligence on the part of another. I accept the State's criticism of the passage from Halsbury referred to. However, it is clear that his Honour did not apply that test to the facts of the case as he had found them. In my opinion his finding was completely in accord with the test as set out by Walsh JA in Sara namely, that to succeed the defendant must establish that the plaintiff "with sufficient knowledge voluntarily accept the risk of physical injury". It was that requirement which his Honour considered had not been established. 305 The State interests then submitted that the primary judge erred in that he did not analyse with sufficient particularity either the question of voluntariness or risk (appreciation of which was required) and voluntary acceptance of which was necessary. With respect to the first of these matters, it is clear that his Honour accepted that Mr Mulligan's decision to dive was a matter of free choice on his part and was, in that sense, voluntary. The basis of his Honour's rejection of the defence was the failure of the defendants to establish that he fully comprehended the extent of the risk; nor did he, with a full appreciation of the risk, voluntarily accept the risk of physical injury in that he had (wrongly) assumed that it was safe to repeat his dive where he did and in the manner he did. 306 The State interests further submitted that his Honour erred in failing to find that Mr Mulligan did have "sufficient knowledge" of the relevant risk. Although it is clear that Mr Mulligan was aware that there were dangers associated with diving into water of unknown depth, it is apparent that his insufficient knowledge of the relevant risk was determined by the primary judge on the basis of his findings that he had already dived six or seven times without mishap, that he had actually assessed the water depth during those dives and had, on his last dive, waded out into the water until it reached his thighs, thus he assumed that he could dive safely. Although he was wrong in this assumption, it highlighted for his Honour the insufficiency of his knowledge of the relevant risk. To adopt the words of Mason P, with whom Meagher and Heydon JJA agreed, in Moore v Woodforth [2003] NSWCA 9 at [32], "This was not a case where it was proved that the plaintiff fully comprehended the extent of the risk and chose to accept or ignore it…or otherwise conducted himself so as to attract the very demanding standards of this ill-defined defence" See also Woods v Multi-Sport Holdings Pty Ltd at 499 [125]. 307 I have already referred to the primary judge's finding that Mr Mulligan did not regard his precise activities in the creek as dangerous. At [341] he said this: "He did not, however, regard the type of diving and swimming he was doing in the second area of the creek as dangerous and this was so, first, because of the assumptions he had made; and secondly, because of his life experience as a swimmer to that point of time" 308 The State interests submitted that his Honour erred in this finding as Mr Mulligan knew that it was dangerous to dive into water of variable depth and he knew the water in the creek to be variable. It was plainly dangerous of him to execute any kind of dive unless he established how variable. 309 Whether or not Mr Mulligan's conduct, objectively considered, was dangerous may be relevant to the issue of obviousness but in my opinion it is not relevant to the present issue. In Canterbury Municipal Council v Taylor [2002] NSWCA 24, Ipp JA, with whom Spigelman CJ and Mathews A-JA agreed, stated the principle in the following terms (at [144] omitting citations): "For the defence to succeed it must be shown that the plaintiff fully appreciated the risk and, by voluntary choice, elected, agreed or consented to accept the risk". 310 After citing from the judgment of Burt CJ in Jeffries v Fisher [1985] WAR 250 at 253 the proposition that although appreciation and acceptance of the risk can readily be inferred from knowledge, knowledge alone is insufficient, Ipp JA observed that it was necessary to consider whether the plaintiff expected that the relevant risk would materialise. This was so because his Honour considered (at [147] omitting citations) that: "[a] belief that the dangers (of which [the plaintiff] had full appreciation) would not materialise, would negative the proposition that he accepted those dangers". 311 In the present case, the primary judge clearly found that Mr Mulligan believed that so far as his activities were concerned, the danger of diving into the creek, albeit of unknown depth, would not materialise. As his Honour said (at [341]), Mr Mulligan: "did not, however, regard the type of diving and swimming he was doing in the second area of the creek as dangerous". 312 Although other criticisms were made of some of his Honour's findings, in my opinion the State interests' challenge to the primary judge's finding that Mr Mulligan did not fully comprehend the nature and extent of the relevant risk fails. This was sufficient to justify his rejection of the defence of voluntary assumption of risk. Contributory negligence 313 Each of Coffs Harbour and the State interests submitted that Mr Mulligan was guilty of contributory negligence. In particular, the State interests submitted that, as a matter of justice and equity, he should bear 90% of the responsibility for his injuries. 314 After stating the relevant principles from the joint judgment of Gibbs CJ, Mason, Wilson, Brennan and Deane JJ in Podrebersek v Australian Iron & Steel Pty Limited (1985) 59 ALJR 492 at 494, the primary judge found that Mr Mulligan did fail to take care for his own safety to the extent that he chose to dive in the creek not knowing the depth of the water in the area into which he dived and in circumstances where the cloudiness of the water and the fast-moving current prevented him from seeing below the surface. His Honour then considered that it was just and equitable that the damages recoverable by Mr Mulligan, should he have been entitled thereto, should be reduced by 15% pursuant to s 9 of the Law Reform (Miscellaneous Provisions) Act 1965. 315 Mr Mulligan submitted that the primary judge erred in holding that he was guilty of contributory negligence in that he had failed to exercise reasonable care for his own safety. It advanced some 24 facts to support the proposition that Mr Mulligan had taken reasonable care for his own safety. 316 In my opinion, most if not all of the matters upon which Mr Mulligan relied were taken into consideration by his Honour: see [346] of his judgment. In particular, a number of them were also recited by his Honour in [340] of his judgment when dealing with the defence of voluntary assumption of risk. It was after dealing with that issue that his Honour turned to the issue of contributory negligence upon the basis that each of the defendants had submitted that in the event that the defence of voluntary assumption of risk was not proved, nevertheless the evidence established that Mr Mulligan was guilty of contributory negligence. It is therefore clear that he took into account when dealing with this issue, the facts and matters upon which Mr Mulligan had relied when contesting the defence of voluntary assumption of risk. 317 The primary judge's conclusion (at [348]) was that Mr Mulligan "was to a moderate degree guilty of failing to exercise reasonable care for his own safety…" In my opinion, this finding was clearly open on the evidence notwithstanding the matters upon which Mr Mulligan relied in challenging this finding. In my opinion, it was inevitable that there should be a finding of contributory negligence against Mr Mulligan. Accordingly, his challenge to his Honour's finding on this issue should be rejected. 318 Both Coffs Harbour and the State interests submitted that his Honour erred in assessing the reduction in Mr Mulligan's damages by only 15%. Accepting that that assessment was based on the respective culpability of the parties and the relative importance of their respective acts or omissions in causing the damage, Coffs Harbour submitted firstly, that Mr Mulligan's voluntary decision to dive into water of unknown depth was causally the most significant factor in his ultimate injury. Secondly, it submitted that if there was a departure from the required standard of care in failing to provide a warning sign, that failure was so marginally on the breach side of the equation as to warrant a significant reduction in Mr Mulligan's damages. 319 The State interests submitted that Mr Mulligan was in complete control of the circumstances and the choices open to him. It further submitted that any breach of duty by the State interests in failing to warn was "insignificant, modest or minor". Accordingly, Mr Mulligan's actions of diving into water into which he could not see and which he knew to be of variable depth as a matter of free choice, was significantly more culpable and demanding of a just and equitable apportionment weighted very much against him. 320 I have already stated at [241] above the principles relevant to the interference by this Court in a primary judge's apportionment of responsibility pursuant to the statute. In my opinion, Mr Mulligan's responsibility for his injuries is significantly less than that of Mr Vairy. Although I would regard a reduction of 15% as being at the bottom of the applicable range, it was not outside that range and, therefore, did not result in a reduction that was either unreasonable or plainly unjust in the sense in which those expressions are used in House v The King. Accordingly, in my opinion this challenge to the primary judge's decision fails. Apportionment between defendants 321 Each defendant cross-claimed against the other seeking contribution or indemnity pursuant to s 5(1)(c) of the Law Reform (Miscellaneous Provisions) Act 1946. The primary judge concluded that the responsibility of the State interests for the damage suffered by Mr Mulligan was greater than that of Coffs Harbour. He considered it to be just and equitable that contribution between the defendants for the amount of any damages that would otherwise have been recoverable by Mr Mulligan (were he entitled to succeed) be borne as to 25% by Coffs Harbour and as to 75% by the State interests. 322 His Honour's reasons for coming to this conclusion are set out in [354] of his judgment in the following terms: "First, the State of New South Wales was the owner of the creek and both reserves. Secondly, between the 1970's and 1996, the Department of Public Works and its successor had a significant and overall supervisory role in relation to matters of control affecting the creek east of the Orlando Street bridge to the ocean and the area of the Jetty Reserve. From 1996, the third defendant had the statutory and de facto control of the Jetty Reserve. Thirdly, while it is true that there are a number of important aspects in which the Council exercised elements of management over the creek, in my view the State interests' role in that regard was superior and, where necessary, paramount. Fourthly, in terms of scientific expertise and economic capability, the State interests were in a decidedly superior position in relation to the ability to understand and control matters relating to the hydrodynamics of the creek when compared to the Council's situation. Fifthly, although the Council had a role to play in relation to the Jetty Reserve particularly in relation to the provision of short term car parking, the pathway and signage, again the paramount supervision and control of the reserve both prior to 1996 and afterwards fell on the State interests. Sixthly, the plaintiff was in fact drawn to the southern bank of the creek when he was traversing the Jetty Reserve and the pathway within it. Seventhly, the primary responsibility for the erection of signage in the southern reserve and on or near the southern bank of the creek especially fell, in my view, on the State interests. This is not to say the Council had no responsibility or opportunities in that regard but the primary responsibility fell upon the Public Works Department and the Jetty Reserve Trust." 323 The State interests submitted that the apportionment adopted by the primary judge was firstly, contrary to the weight of the evidence; secondly, without consideration of the causative actions of each of the relevant defendants; and thirdly, without consideration of the position of the defendants individually. This last ground of challenge was directed to his Honour's lumping of the State interests together. In my opinion, there is no substance in this complaint. 324 The State interests then sought to canvass each of the seven reasons upon which the primary judge's conclusion was based as set out in [354] of his judgment. I do not propose to add to the significant and regrettably unavoidable length of this judgment by repeating those submissions. However, in my opinion they have substance. They raise matters upon which the State interests relied in its submissions in support of Mr Mulligan, that Coffs Harbour owed him a duty of care. They are also matters upon which the primary judge relied in finding that such a duty was owed. I think it is fair to say that, neither in their oral nor written submissions, did Coffs Harbour challenge to any great degree the factual matters upon which the State interests now rely in support of their challenge to his Honour's findings on apportionment. On the issue of no duty, Coffs Harbour's submissions were more narrowly focussed. 325 In light of the material to which I have referred, the State interests submit that in apportioning 75% of responsibility for Mr Mulligan's injuries to them, the exercise of his discretion miscarried. In particular, it was contended that Coffs Harbour had assumed responsibility for the erection of signage including upon the southern bank as evidenced by the signage it had erected with respect to Park Beach being unpatrolled. It was submitted that that assumption of responsibility was the most relevant manifestation of Coffs Harbour's control of the southern bank of the creek for present purposes. If it had assumed responsibility for warning against the perils of an unpatrolled beach, it must also be taken to have assumed responsibility for warning against cognate perils, namely, the variable depth of the creek. 326 In [263] above, I found that Coffs Harbour's duty of care extended at least to the point of the concrete pathway constituted by the eastern boundary of the licensed area beneath the railway bridge and that, had a warning sign been erected at that point, being so close to the unmade diversion from the pathway to the southern bank of the creek, it would have been heeded by Mr Mulligan (as the primary judge found). I was also tentatively of the view (at [264]) that in all probability the better view was that Coffs Harbour's duty of care extended to the whole of the southern bank. 327 In the foregoing circumstances, to hold Coffs Harbour responsible for only 25% of Mr Mulligan's injuries was so unreasonable or unjust in the circumstances as to evince error in the exercise by his Honour of his discretion. Accordingly, it is necessary to reassess the appropriate apportionment. 328 As in the case of contributory negligence, the making of an apportionment as between defendants for their respective shares in their responsibility for the plaintiff's damage involves a comparison of both culpability, i.e. of the degree of departure from the standard of care of the reasonable man, and of the relative importance of the acts or omissions of the respective defendants in causing that damage. The whole of the conduct of each negligent party in relation to the circumstances of the accident must be subjected to comparative examination. 329 The circumstances giving rise to a duty of care on the part of both Coffs Harbour and the State interests have been set out above in relation to that issue. In essence, Coffs Harbour had exclusive control, both de facto and de jure, over the concrete pathway leading from Orlando Road to the eastern boundary of its licensed area beneath the railway bridge. The State interests had both de facto and de jure control over the bed of the creek and its southern bank. However, Coffs Harbour had some influence over the southern bank of the creek insofar as it had participated in the construction of the concrete pathway/cycleway over the Jetty Reserve and as evidenced by its erection of a sign upon that pathway warning of the fact that the beach was unpatrolled. In my opinion, each of Coffs Harbour on the one hand and the State interests on the other were essentially equal in terms of their responsibilities with respect to those members of the public, such as Mr Mulligan, who swam in the creek from the southern bank. 330 The only breach of the duty of care alleged against each defendant was its failure to erect a warning sign. Had that failure been such a breach, then the respective duties of care would have been satisfied by the erection of a warning sign by Coffs Harbour just inside the eastern boundary of its licensed area under the railway bridge and by the State interests and, in particular, the Trust, by erected one or two signs in an appropriate location upon the southern bank and, in particular, at the access point to that bank from the dirt path leading from the pathway/cycleway. In these circumstances, it seems to me that, again, the culpability of the defendants was equal. 331 Accordingly, taking account of the factors to which I have briefly referred, I would consider it to be just and equitable that contribution between the defendants for the amount of the damages that would have been recoverable by Mr Mulligan, were he entitled thereto, ought to be borne as to 50% by Coffs Harbour and 50% by the State interests. Damages 332 In assessing damages upon the assumption that Mr Mulligan was entitled thereto, the primary judge awarded damages in respect of domestic and nursing care (both past and future) required by Mr Mulligan including that provided by the Irish Wheelchair Association. In so doing, and consistent with the decision of the High Court in Van Gervan v Fenton (1992) 175 CLR 327 at 333-334, his Honour assessed those damages by reference to the market cost or commercial rate of providing those services rather than, as was submitted by the defendants, by reference to the rates at which the services were actually provided. Coffs Harbour formally submits that in so doing his Honour erred. However, it recognised that the decision of the High Court in Van Gervan bound him to find as he did: this Court is also bound by that decision. Accordingly, the challenge to this aspect of his Honour's finding of assessment of damages fails although Coffs Harbour has reserved its position with respect to the correctness of the decision referred to. 333 In determining the quantum amount of past economic loss, it was submitted to the primary judge that he ought to have deducted from that loss the income received by Mr Mulligan by way of rental of a house at Arbour Hill which he had purchased prior to the accident but in which he is now unable to live as the building is unsuitable for modification to accommodate his needs resulting from his extensive injuries. It was submitted by Coffs Harbour that when a plaintiff is awarded compensation he should not be better off financially than if he had not been injured. Had he not been injured, Mr Mulligan would have lived in this house and paid his mortgage out of his earnings with the Irish Railways Department. Coffs Harbour thus submitted that Mr Mulligan will be compensated for loss of past earnings but his mortgage repayments will now be made out of rents and not out of the compensation for lost earnings. Accordingly, it was submitted he will be better off than if he had not been injured. 334 The primary judge (at [361]) queried whether Mr Mulligan could in any sense be said to be better off as a consequence of receiving compensation than if he had not been injured. Furthermore, even if it were true that, in a narrow sense, he would be better off, "the consequence would be to penalise a thrifty and prudent plaintiff at the expense of the unwise and wasteful. Such a consequence would be repugnant to common sense." 335 His Honour then referred to the analysis of this topic by Windeyer J in National Insurance Co of NZ Limited v Espagne (1961) 105 CLR 569 at 588-599 and concluded (at [362]): "The principles spelled out by his Honour make it quite clear that the plaintiff's rent monies could not possible fall into the category of a subvention that was intended to accrue to the benefit of the defendant. There being no other basis for the argument advanced by the defendants, it must fail." 336 Coffs Harbour repeats before this Court the submission made by it to the primary judge that Mr Mulligan should not be placed in a better position after the accident than he was before it as a consequence whereof he was required to give credit for income received which would otherwise not have been received and in relation to which there was no "special characteristic" such as would entitle him to retain both. It was submitted that the rental income from the Arbour Hill property was not a subvention as a consequence whereof the decision in Espagne did not require that those amounts accrue to the benefit of Mr Mulligan rather than to the benefit of the defendants. 337 In Espagne, Windeyer J said (at 597): "Damages are given as compensation for the consequences of a tortious act when the harm is of a kind that a reasonable man could have foreseen. Consideration of cause and consequence are thus necessarily involved in the assessment of damages. But in cases such as this the question is not whether a harm that the plaintiff has suffered is, in the relevant sense, a consequence of the defendant's negligence, but whether an advantage that the plaintiff has gained is to be regarded as mitigating that harm. Causal considerations cannot be decisive of the latter question, unless there be a general rule of law that all benefits, or foreseeable benefits, received by an injured person because of, or as a consequence of, his injury are to be set-off against the damages he can recover from a wrongdoer. In my view, there is no such rule." 338 After further discussion of the principles relevant to aid given by friends and philanthropic persons to ameliorate the loss of an injured person, his Honour stated the governing principles as follows (at 599-600): "In assessing damages for personal injuries, benefits that a plaintiff has received or is to receive from any source other than the defendant are not to be regarded as mitigating his loss, if: (a) they were received or are to be received by him as a result of a contract he had made before the loss occurred and by the express or implied terms of that contract they were to be provided notwithstanding any rights of action he might have; or (b) they were given or promised to him by way of bounty, to the intent that he should enjoy them in addition to and not in diminution of any claim for damages." See also per Dixon CJ at 573; Diamond v Simpson (No. 1 ) [2003] Aust Torts Rep 81-695. 339 It may well be, as Coffs Harbour submits, that any rental received by Mr Mulligan in respect of his Arbour Hill property does not fall within the principles articulated by Windeyer J in the above passage in that that rental does not constitute a subvention given out of benevolence. Nevertheless, the question remains whether that rental is to be regarded as otherwise mitigating his loss. 340 Certainly, it could not be said that the tenant who paid the rent intended that it should be used to relieve the defendants from fully compensating Mr Mulligan in respect of his injuries. Thus, in Redding v Lee; Evans v Muller (1983) 151 CLR 117, Mason and Dawson JJ, with whom Wilson and Deane JJ in substance agreed, explained the Espagne approach as follows (at 137): "The subsequent decisions in this Court apply the principles expressed by Dixon CJ and Windeyer J in Espagne . They make it clear that the issue turns on the character and purpose of the particular financial benefit which the plaintiff receives: was the benefit conferred on him independently of any right or redress against others and so that he might enjoy the benefit even if he enforced the right?" 341 Although this and other authorities concerned with the "Espagne approach" were dealing with gratuitous payments or benevolent services, I see no reason in principle why that approach cannot be applied to any payment received by an injured plaintiff from a third party. The question should always be: was the payment made with the intention that it should result in the reduction of damages recoverable by the injured party? In the present case, the answer to that question must be in the negative. 342 Mr Mulligan nevertheless submitted that no credit should be given for that rental for two reasons. Firstly, it was submitted that he is not receiving a collateral benefit because if the accident had not occurred, it would have been open to him in any event to live with his parents and pocket the rent he received from his own property. Secondly, it was submitted that any collateral benefit arising from the receipt of rent is a consequence of an act of benevolence on the part of Mr Mulligan's parents (with whom he lives) namely, by not demanding rent from him for living at their home. If that rent is the equivalent of the rent received by him from his own property, then the principle referred to by Windeyer J in Espagne would be applicable. 343 Mr Mulligan further submitted that the benevolence of his parents might not be a situation upon which he can rely for the rest of his life. His parents may start demanding rent from him or they may die, move house or divorce, in which event he would have to buy a new house with appropriate modifications or in some way move back into his own house. It was submitted that the receipt of rent was merely a buffer against these contingencies. 344 In my opinion, Mr Mulligan's submissions have substance. He had purchased the house before his accident and the fact that he is unable to reside therein is not due to any conduct on his part but on the contrary, to the negligent conduct (if such it be) of the defendants. Rather than receive rent, it would be open to Mr Mulligan to leave his house vacant or to permit a family member or friend to occupy it rent-free. In these circumstances, the defendants would have no claim in respect of rental, which was neither demanded nor received. I do not consider that Mr Mulligan should be worse off because, at least for the time being, he has decided to rent the property in which, but for the accident, he would have resided. Accordingly, I would reject Coffs Harbour's challenge to this aspect of his Honour's assessment of damages. Conclusion 345 I would propose the following orders: Wyong Shire Council v Vairy CA 40083/03: a) Appeal allowed; b) Set aside the orders made by Bell J on 20 December 2002; c) Verdict and judgment for the defendant; d) The plaintiff to pay the defendant's costs of the proceedings and of the appeal but in respect of the latter to have a certificate under The Suitors Fund Act 1951 if otherwise entitled. Mulligan v Coffs Harbour City Council & Ors CA 40292/03 a) Appeal dismissed with costs. ********** Last Modified: 12/16/2004 DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. 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