Supreme Court New South Wales Medium Neutral Citation: Hume v Patterson [2013] NSWSC 1203 Hearing dates: 8, 9, 10, 11, 12 October 2012; 25, 26, 27 March 2013 Decision date: 30 August 2013 Jurisdiction: Common Law Before: Campbell J Decision: 1) Judgment for the plaintiff on the question of liability with damages to be assessed; 2) The defendant to pay the plaintiff's costs of the determination of the separate question of liability forthwith after they have been agreed or assessed; 3) List the matter for directions before the Common Law Case Management Registrar at 9:00 am on Friday 27th September 2013. Catchwords: TORTS - negligence - plaintiff suffered catastrophic injury while participating in sport of wakeskating - determination of liability as separate question- whether defendant tow boat driver was in breach of his duty to exercise reasonable care for the safety of the plaintiff in the conduct of the activity - whether wakeskating dangerous recreational activity Legislation Cited: Civil Liability Act 2002 (NSW) Civil Liability Amendment (Personal Responsibility) Act 2002 (NSW) Evidence Act 1995 (NSW) Uniform Civil Procedure Rules 2005 (NSW) Cases Cited: - Dovuro Pty Ltd v Wilkins [2003] HCA 51; 215 CLR 317 - Echin v Southern Tablelands Gliding Club [2013] NSWSC 516 - Fallas v Mourlas [2006] NSWCA 32; 65 NSWLR 418 - Falvo v Australian Oztag Sports Association [2006] NSWSC 17 - Imbree v McNeilly [2008] HCA 40; 236 CLR 510 - Jones v Dunkel (1959) 101 CLR 298 - Lormine Pty Ltd v Xuereb [2006] NSWCA 200 - Paric v John Holland Constructions Pty Ltd [1985] HCA 58; 59 ALJR 844 - Rootes v Shelton (1967) 116 CLR 383 - Wallace v Kam [2013] HCA 19; 87 ALJR 648 -Wyong Shire Council v Shirt (1980) 146 CLR 40 Category: Principal judgment Parties: Martin Hume (plaintiff) Timothy John Patterson (defendant) Representation: Counsel: Dr AS Morrison SC and A Campbell (plaintiff) GJ Parker SC (defendant) Solicitors: Gerard Malouf & Partners (plaintiff) HWL Ebsworth (defendant) File Number(s): 2010/379172 Judgment 1The plaintiff, Mr Martin Hume, suffered a catastrophic injury at around 2:10 pm on 18th November 2007 when participating in the sport of wakeskating on the Tweed River in northern New South Wales. As a result of a fall he suffered C6 tetraplegia. By statement of claim filed 15 November 2010 he brings a claim in negligence against Timothy John Patterson, the driver of the boat behind which the plaintiff was being towed at the time. A claim against the owner of the boat, was discontinued by notice filed 9 March 2011. 2The substance of the plaintiff's claim, which the defendant denies, is that the defendant negligently drove the boat outside the navigation channel causing him to strike his head on a sandbar when he fell, resulting in his injury. This judgment determines the question of liability only by dint of an order made by Johnson J on 6th May 2011 under r. 28.2 Uniform Civil Procedure Rules 2005 (NSW). 3There is no dispute that the plaintiff's injury was caused by his head colliding with a firm, unyielding surface with his neck in flexion. The key issues are whether the incident occurred within the navigation channel; whether the plaintiff struck the riverbed, or an unseen submerged object; if the former, the depth; negligence and causation; and whether the plaintiff's injury resulted from the materialisation of an obvious risk of a dangerous recreational activity. 4There is no question in this case that the driver of a towboat owes a duty of care to the towed wakeskater to exercise reasonable care in the control and management of the vessel to minimise the risk of personal injury. Equally there is no serious issue that if the defendant navigated the towboat outside the channel he was in breach of that duty because there the depth of the river was uncertain and variable, being foreseeably too shallow in places for the reasonably safe performance of the activity. It is otherwise if the activity took place wholly within the channel. The sport of wakeskating 5The sport of wakeskating is described in exhibit 7A, an expert report prepared by Jack Ellison, a professional boat driver, jet ski rider and water skier, in the following terms at [10]: Wakeskating is a surface water sport which involves riding a wakeskate over the surface of a body of water whilst being towed by a boat. Wakeskating is an adaption (sic) of wakeboarding with similar boards except the most notable difference is that a wakeskate has no boots and a wakeboard has boots which keeps you bound to the board. 6The 'wakeskate' board is described by Mr Ellison as follows at [13]-[15]: 13. A wakeskate board is manufactured from maple or from fibreglass... The top surface of the board is covered with a non slip, soft high-traction foam rubber material or grip tape similar to the surface of a skateboard. The foam rubber material provides some protection in an event that you fall off and also allows the rider to ride he wakeskate barefoot... 14. The shape of a wakeboard is isometric and can be ridden either forwards or backwards, the size of the boards varies from 100cm to 115cm long ad approximately 40cm wide. A wakeskate usually does not have a sharp edge which limits aggressive edging and reduces the risk of a face plant. 15. The board has a small fin on either end to assist in tracking and manoeuvring of the board. The average size of the fin is 170mm and 12mm deep. The fins can be manufactured from aluminium, fibreglass or plastic. 7The absence of foot straps, or boots, binding the skater to the equipment is one aspect of wakeskating which is of some significance as explained below. 8Waterskiing, wakeboarding and wakeskating as recreational pursuits are undertaken at slower speeds than ski-racing and other professional or display events within the genre. Recreational waterskiing using two skis is conducted in the range of 20 to 35 knots per hour, a little faster on one ski, at 30 to 40 knots. Recreational wakeboarding is conducted at between 15 and 20 knots per hour and wakeskating within the same range, but perhaps 10 or 15 per cent slower (414.10 - .20T). 9A wakeskate is, obviously, much wider than a waterski, and somewhat wider than a wakeboard. It is this additional surface area which permits the activity to be undertaken at a slower speed. The relatively low speed, and lack of binding, facilitates the type of stunts and tricks that may be undertaken, which are similar to the manoeuvres performed on a skateboard (413.35 - 414.5T). 10Mr. Ellison expressed the opinion that the minimum safe depth for the conduct of wakeskating is 1.5 metres. This is based upon what might be referred to as practice in the field, rather than upon any formal risk assessment extending to the risk of a participant hitting the bottom (403.5 -30T; 414.35T; exhibit 7A [34]; exhibit 7C [15]). 11Mr. Ellison is of the view that the risk of injury while riding a wakeskate is very low (exhibit 7A [71]; 400.10T). He is only aware of minor injuries having occurred by a falling skater "just hitting the water" (409.10T). He put this down to the relatively low speed at which the activity is conducted. He said, "the impact when you fall off a wakeskate and hit the water is a lot less than falling off while water skiing" (exhibit 7A [72]). As there are no bindings connecting the skater to the board, the risk of ankle or knee injury when falling is reduced, if not eliminated. He is unaware of any case of a wakeskater or wakeboarder falling and sustaining injury by striking the bottom (exhibit 7C [14]). 12Mr. Ellison has great experience as a champion competitor and coach in various forms of water skiing including wakeskating. He has been a national wakeskating champion. He is a nationally accredited level two coach and has held appointments as coach of overseas national teams. He has also produced or directed a number of water sport "spectaculars" and co-ordinated water action events for film, including James Bond films. 13His evidence is that it is very common for novice waterskaters to fall. Other evidence is to the effect that falling is an inevitable incident of the sport (Mr. Woodford at 191.10-22T)). Mr. Ellison said his experience of teaching people to wakeskate suggests that it is normal for the novice to fall up to ten times in a session of around 20 minutes (exhibit 7A [74]). At exhibit 7A [75] - [77] he said: I have personally ridden a wakeskate over the past 10 years and have also coached many hundreds of people at my ski school on how to use a wakeskate. I have witnessed many people falling off the wakeskate while learning to do a deep water start and also while up and going. On average a person may take up to 10 attempts to successfully do a deep water start on a wakeskate. I have never received any injuries myself while on a wakeskate and have never witnessed any serious injuries while I have been coaching people to ride a wakeskate. I have witnessed injuries of people while riding a wakeskate and falling off which include: sprains, bruises and broken arms from becoming entangled in the water ski handle. 14To avoid entanglement, the proper technique is simply for the rider to release the ski handle as soon as he or she commences to fall. The impression one forms from Mr. Ellisons's evidence, including his written reports, is that only minor injuries are involved in this variant of waterskiing, and that such injuries as do occur affect "only a very small percentage of the people that wakeskate" (exhibit 7A [80]). Notwithstanding his experience, he was of the view that there are inherent risks which include the following (exhibit 7A [81]): a)Running into something submerged below the water surface; b)Risk of injury when falling off; c)Risk of drowning when falling off; d)Risk the boat could run over you; e)Risk of falling off and becoming entangled in the ski rope. I infer that some of these risks are theoretical, in the sense that on his evidence he has not witnessed incidents falling into at least some of the categories he identifies. He has no experience of catastrophic injury involving wakeskating and considers the prospect "highly unlikely" (exhibit 7A [82]). Indeed across the wide variety of waterskiing he knows of two serious spinal injuries only. One involved, I infer, a highly skilled performer in a display at Sea World who collided with a wharf whilst performing a misjudged ski jump. The other involved a ski-racing competitor. Ski-racing is performed at speeds of in excess of 100 miles per hour. The competitor fell at that high speed and suffered a spinal injury hitting the water (400.45 - 401.20T). 15It is convenient to interpolate that I heard other evidence relevant to an evaluation of the risk of injury in this sport. Associate Professor Yeo, a leading medical expert in the field of spinal injury, gave evidence. Professor Yeo is, of course, a very eminent specialist. For the obvious reason that his expertise is in medicine, he was not able to distinguish amongst the many variants of waterskiing in giving evidence. He was unfamiliar with wakeskating (307.38T). He assumed that the plaintiff was waterskiing (307.4T). With great respect, then, in this case his evidence is not very pertinent to the question of risks arising from the sport. I formed the impression that most of the many serious spinal cord injuries seen by him involve motor vehicle accidents (304.35T). Most of the "water related accidents", which together amounted to five to eight per cent of the cases seen each year at the Spinal Unit at Royal North Shore Hospital, involve "diving into shallow water in pools where alcohol plays a part" (304.50T). He has experience of "waterskiers" who suffer traction injuries involving the brachial plexus, and he said (304.20T): Not so much spinal cord injury and certainly not so much fracture [of the bony processes of the spine] unless you had an impact aspect to the fall from the ski such as into the bank. 16Professor Yeo had sat in Court during some of the concurrent evidence of two biomechanical engineers. During his evidence he said he had been involved in some of the research involving inquiry into the risk of diving injury referred to by those experts. Professor Yeo described the plaintiff's injury as "a compression fracture of the vertebrae" of the cervical spine. He said of the injury (302.50T): It was a high impact injury and it must have occurred in a fairly shallow depth of water. Professor Yeo, understandably, was not able to better quantify "a fairly shallow depth of water", and, from the point of view of the spinal specialist, he said that to avoid the risk of spinal injury when diving "[the] water has to be as deep as the person is tall" (303.25T). 17Dr. Andrew McIntosh and Dr. Tom Gibson are both highly qualified biomechanical engineers. In their joint report (exhibit T) they agreed that the plaintiff's "cervical spine injuries were caused by flexion and compression loading of the cervical spine most likely when his head contacted the bottom of the channel" (exhibit T, 2.1 [4]). I understood the reference to the bottom of the channel to be to the riverbed. I did not understand them to purport to say where in the river the accident occurred. Their opinion as to likely cause accords with Professor Yeo's. 18Amongst other matters agreed was the following (exhibit T, 2.4[11]): The experts agree that there are many factors that contribute to the causation of this injury including the impact velocity of the head, the neck posture on impact, the weight of the plaintiff, the type of surface impacted and vector of the impact force. Of these, head speed at impact is critical (278.10 - .15T). The plaintiff is 183 cm tall and as at the date of the accident weighed 100 kg. As a sandy riverbed has some give, it may indent on impact, "capturing" the person's head and increasing the risk of neck injury (262.45-263.40T). The velocity vector is the angle, or direction, of travel of the person on impact (exhibit 6, p.13, Fig.6). 19As Professor Yeo indicated - so too the biomechanical engineers - most of the research in this area is concerned with either an examination of the biomechanical forces relating to diving into swimming pools, or the review of the effects of diving injury. There is no question between the parties that this research has something to offer in the present discussion, as when the plaintiff fell from the wakeskate he pitched forward head-first, like a diver. 20Applying the considerations expressed at [18] above, and additionally assuming: a horizontal speed of 15 to 20 knots, equivalent to the boat speed, or 7.7 to 10.3 metres/per second; a maximum vertical speed of the plaintiff's head upon entry of 6.0 m/s based on falling from his standing height, rather than from the elevated position suggested by some of the evidence; and an angle of entry to the water of 30 to 45 degrees, the bio-mechanical experts agreed that for a person of the plaintiff's height and weight: (a)at 1 metre depth, the risk of catastrophic injury is high (272.35 - .50T); (b)at 1.5 metres, there is a substantial risk of catastrophic cervical spine injury (280.5 - .10T); (c)at 2 metres, the risk of such injury occurring is assessed as possible, but unlikely (273.5T; 279.25T); (d)at 3 metres, such an injury is "highly unlikely" to occur (273.20T - .35; 278.30; 279.25T). 21As there is reference to it elsewhere in these reasons, I will set out my understanding of a deepwater start. Mr Ellison described this as a procedure for a beginner getting up out of the water on a wakeskate. The evidence before the Court, to which I will refer, indicates the plaintiff had not long completed such a manoeuvre at the time he fell. Mr Ellison described of a 'deep water start' in the following terms (exhibit 7A, [33]-[38]): 33. Before getting up, you should be able to do the following things: (a) Be comfortable in the water behind a boat (b) Be wearing a [personal floatation device] (c) Be able to pull yourself up from the sitting position 34. When preparing to get up, lay the board in the water perpendicular to the boat with the grip side up. Lay flat on your back perpendicular to the board and place your heels on the top of the board. Keep the rope in both hands around your belly button. 35. At this point, ask the boat driver to put the boat in gear, giving a little tension to the rope. This will help you stay balanced over the board as you will have something to hold on to. When the driver starts to give the boat a little more throttle, the board will turn up to the bottom of your feet and the pressure of the water will help to keep your feet on the board. 36. After the board lines up to your feet, relax and completely bend your knees allowing your knees to meet your chest. Keep the rope out in front of your knees. Once in this position, you are almost up as the boat can accelerate slowly up to a Wakeskating speed. 37. As you come out of the water you should be in a squatted position and the rope out in front of your knees. Now you should slowly stand up and apply the most pressure to the foot that will be in the back and push the ski rope handle in to your leading hip. You may also find it easier to let go with your back hand in order to get your body in the correct riding position. 38. Once you are up and gliding over the surface of the water the correct technique is to have equal pressure on both of your feet with your knees slightly bent. 22I accept the evidence I have summarised in this section from [5]. I appreciate there may be a tension between the evidence of Mr. Ellison set out at [10], on the one hand, and the evidence of Professor Yeo at [16], and Dr. Gibson and Dr. McIntosh at [20], on the other. But it may be unsurprising that Mr. Ellison's practical view based upon his experience in the field differs from the approach of medical and biomechanical experts. The towing vessel 23The towing vessel was a Cruise Craft "Resort" model powered by a Yamaha 225HP outboard motor. The defendant borrowed it from a friend, but he was accustomed to driving it. This model of boat is depicted in annexure C to exhibit 7A. Mr. Ellison rode in the boat as a passenger when the defendant drove it on the occasion of a view conducted for the purpose of Mr Ellison preparing his report. The actual vessel is depicted in various photographs in the body of his report. Close up photographs of the stern of the boat showing the ski pole for attachment of the towrope, the outboard motor, propeller and skeg are reproduced on page 28 of the report. The skeg is a fin-like protrusion below the propeller. 24In exhibit 7D, Mr. Ellison said that a boat like that being driven by the defendant is able to operate "on the plane' in shallow water of approximately one metre in depth. By "on the plane" I understand him to mean at cruising speed with its hull in a more or less horizontal plane. It may be otherwise when the vessel is accelerating from a stationary start with its hull angled more towards the vertical because the outboard motor is lower in the water. In such a manoeuvre, in water of one metre in depth "there is an increased chance that the skeg would hit the bottom of the river" (exhibit 7D [4](b)). This could slow the boat "or even possibly stop it". 25Unfortunately, Mr. Ellison did not take the opportunity to measure the boat driven by the defendant at his view. He sought to support this opinion by examination of a similar boat of a different make, sporting an identical motor. A photograph of this boat was annexed to the exhibit as annexure A. Objection was taken to the tender of the photograph, which I admitted provisionally. 26After some cross-examination, I rejected the photograph annexed to exhibit 7D for reasons I expressed at 397.45 - 398.10T. I marked the photograph MFI 15. I was not satisfied that the evidence was relevant because it did not seem to me on the evidence of Mr. Ellison that I could be satisfied that there was sufficient similarity of hull dimension, manner of fixation of the outboard motor and the like to render the later inspected vessel a meaningful guide to the dimensions of the vessel involved in the accident. By this I mean that the evidence did not establish sufficient similarity between the two vessels: Paric v John Holland Constructions Pty Ltd [1985] HCA 58; 59 ALJR 844. 27Moreover, Mr. Ellison made it clear that he had conducted recreational wakeskating at a depth of one metre (403.5T; 414.25 - .30T). The evidence in this case, which both parties accept, is that when the plaintiff fell the vessel was being driven at a speed of 15 to 20 knots. This is cruising speed for this type of activity and it is very likely that the vessel was "on the plane" rather than at a more vertical angle, even if, as seems to be the case, the plaintiff fell soon after he had completed a deep water start, and was upright on the wakeskate. It seems to me, therefore, that the vessel involved in the accident could have been navigated in water one metre deep at the time of the accident without difficulty. Whether it was in such shallow water is the central factual dispute in the case. 28Notwithstanding that Mr. Ellison has wakeskated at a depth of one metre, indeed 900 mm, he was of the view that it was unacceptable for a tow boat driver to navigate a boat in the stretch of the Tweed River with which I am concerned outside the marked navigational channel, and in the near vicinity of the sandbar: (402.45 - 403.5T). The defendant gave evidence to the same effect (340.35 - 341.10T). He explained that there is shallow water over a sandbar and that there is the potential for the skater to hit the sandbar if the boat navigated outside the channel. I understood that the defendant meant there was the potential for the skater to fall and hit the sandbar rather than skate into it. The Tweed River at Chinderah Bay 29Exhibit A is a boating map of the lower Tweed River and Cudgen Creek, published by New South Wales Maritime (now Roads and Maritime Services) and printed in August 2011. It depicts the stretch of the Tweed River, approximately one kilometre south of the Barneys Point Bridge, at Chinderah, where the accident occurred. The river at this location runs from south to north, flowing towards its mouth at Tweed Heads, on the New South Wales and Queensland border. The river bends at Chinderah, switching from running generally northeast to generally north. The accident occurred near this bend. 30There is a channel marker at the bend, labelled number 021 on exhibit A ("the marker"). It marks the western extremity of the channel, approximately 75 metres from the eastern shoreline. The eastern shoreline consists of a rock retaining wall interrupted by a boat ramp. To the west of the channel marker the river opens up considerably into Chinderah Bay. Chinderah Bay is of variable depth because of the presence of an extensive sandbar. Between the eastern shoreline and the marker is a channel of deep water. Marker 021 is a starboard marker for vessels heading downstream. 31Exhibit A is colour-coded. Differing shades represent the approximate depth of water in metres over different parts of the river. The depth of the water in the middle of the channel in this stretch of the river is indicated as being between five and ten metres. The depth scale indicates that the water becomes shallower as one moves west from the middle of the channel, past the marker, toward and over the sandbar. The chart indicates a depth of between two and five metres at the marker. The area to the west of the marker - that is the area outside of the channel - is indicated as an area of zero to two metres in depth. 32Mr Carl Cormack, a Boating Safety Officer with Roads and Maritime Services, provided further evidence about water depth in this stretch of the Tweed River based on his investigation of this incident in the course of his duties. Mr Cormack visited the site at Chinderah on 8th March 2008 and used the depth sounder and GPS device on his boat to plumb various points around the river. He made a contemporaneous handwritten record of his results, which was tendered by the plaintiff without objection and marked exhibit B. 33After examining a 'tide table' to make adjustments for the tidal conditions prevailing at around 2:10pm on 18th November 2007. His evidence is that the depths recorded on exhibit B would each have been 33 centimetres shallower when the plaintiff suffered his injuries. 34The depths recorded by Mr Cormack, adjusted for the conditions prevailing on the day of the incident, are as follows (exhibit B, 19.35-20.5T): a)Around the marker, a depth of approximately 3.07 metres. b)Fifteen metres to the west of the marker, a depth of approximately 1.67 metres, and c)Thirty metres to the west of the marker, a depth of approximately 67 centimetres. 35Mr Cormack agreed with senior counsel for the plaintiff that "on [these] soundings there was no shallower water than at least two to three metres until [he] got to the west of the buoy" (18.25T). 36These soundings were supplemented by further evidence from Mr Cormack, taken on 10th October 2012 during a 'view' of the location of the incident, conducted pursuant to s 53 Evidence Act 1995 (NSW). The purpose of the view was for better understanding of the evidence about tidal and other conditions prevailing at the time of the incident. Mr Cormack's evidence at that the time was the tide was ebbing. Low tide was an hour and a half away (208.5T); whereas at the time of the incident the tide was incoming, approximately two and a half hours before high tide (207.50T). The net effect of this is that in order to replicate the depth of the water at the time of the plaintiff's accident it was necessary to add approximately 40 centimetres to the soundings obtained at the view (209.45-210.10T, 211.5T, 216.10-15T, 218.10T). 37The measurements taken at the view, adjusted for the conditions prevailing on the day of the incident, are: In the channel Around the marker West of the marker At approximately the middle of the channel, a depth of 8.2 metres. Approximately ten metres south (upstream) of the marker, a depth of 3 metres; Approximately twenty metres west of the marker, a depth of 2.9 metres; Approximately ten metres south (upstream) of the marker a depth of 4.3 metres; Approximately twenty metres west of the marker, a depth of 2.3 metres; Approximately five to seven metres north (downstream) of the marker, a depth of 5.3 metres Approximately twenty five to thirty metres west of the marker, a depth of 2 metres; Approximately thirty five to forty metres west of the marker, a depth of 1.1 metres; At approximately forty metres west of the marker, a depth of 1.3 metres; Approximately forty five to fifty metres west of the marker, a depth of 0.7 metres. 38The apparent inconsistencies in some readings in the table are due to the delay in recording the detail which altered as the vessel plied across the river. When counsel could not agree a second reading was taken. Moreover Mr Cormack's course on 8th March 2008 was susceptible of only approximate replication. Doing the best I can, I find that the evidence in exhibit B taken together with the evidence on the view supports the following depths: a)At the middle of the channel - 8.2m; b)Around the marker - between 3m and 5.3m; c)Twenty metres to the west of the marker - between 1.7m and 2.9m; d)Thirty metres to the west of the marker - between 0.7m and 2m; e)Forty metres to the west of the marker - between 1.1m and 1.3m; f)Forty five to fifty metres to the west of the marker - 0.7m. 39The depth of the water around the marker at 2:10pm on 18th November 2007 was between 3m and 5.3m. 40This evidence establishes that the river becomes steadily deeper moving east from the eastern shelf of the sandbar, past the marker and towards the centre of the channel. This is consistent with the evidence of Mr Neil Sutherland, a hydrographer (370-372T). From his examination of cross sectional data recorded at two locations along the eastern shelf of the sandbar (which he referred to as the "shoal"), he concluded that "the shoal increases in depth relevantly at no more than 0.2 metres over a 5 metre distance" moving from west to east (affidavit of Neil Mathew Sutherland 31 October 2012 at [9]; see also drawing numbers 12 and 13 annexed thereto). Mr Sutherland gave further evidence based upon his examination of aerial photographs, which I accept, that the shoal has not moved materially since the incident (affidavit of Neil Matthew Sutherland 10 October 2012 at [12].) 41Mr Sutherland also gave evidence that, based on experiments he conducted under tidal conditions comparable to those prevailing around the time of the incident, if the plaintiff drifted after falling from his wakeskate he would have done so in a south-easterly direction (371.5T; 372.20T), which, I interpolate, is away from, rather than towards, the sandbar. 42There is a difference between the range of depths recorded by Mr Cormack, both in March 2008 (forming exhibit B) and on the view, on the one hand, and the depth scale depicted on exhibit A, on the other. The main difference is that water at least three metres deep was recorded around the marker in exhibit B and on the view, whereas exhibit A indicates that the minimum depth in this area is two metres. These differences may be explained by the fact that exhibit A contains a disclaimer as to its accuracy and is therefore presumably to be used as a guide only. Moreover the river is tidal at Chinderah Bay and the chart doubtless takes account of variations due to the tide. The depth soundings taken by Mr Cormack have been adjusted in an attempt to replicate conditions at the time of the accident. Exhibit A does not cause me to alter the findings recorded at [38]-[39]. The events of 18 November 2007 43The plaintiff's evidentiary statement, dated 28 March 2011, was admitted without objection and marked exhibit D. On the day of the accident the plaintiff had been working at the Coles supermarket at Tweed Mall. He finished his shift early and proceeded to the Chinderah Boat Ramp where he met the defendant and various other friends, including Bryan Woodford and Scott Nipperess, each of whom gave evidence. The plaintiff and his friends were all very young men at the relevant time. When the plaintiff arrived the defendant was navigating the boat to the ramp, where Mr Nipperess, and some others whom the plaintiff did not identify, alighted. The plaintiff got into the boat with Mr Woodford, as observer, and the defendant as driver. The trio entered the channel. 44The plaintiff put on a lifejacket and entered the water to wakeboard. Mr Hume had experience wakeboarding, having undertaken the activity since the age of sixteen, including on at least ten occasions in the two years leading up to the accident, each time on the Tweed River (exhibit D at [10], [13]). From the stretch of river adjacent to the Chinderah boat ramp, the plaintiff was towed upstream (in a southerly direction) toward Murwillumbah, during which time he "got up on the wakeboard a few times... [and] came off a couple of times". At this point, the defendant turned the boat around, and headed downstream, in a northerly direction. Soon after, the boat stopped and the plaintiff switched from the wakeboard to a wakeskate. The plaintiff had never wakeskated before (exhibit D at [18]). 45Heading downstream on the wakeskate, it was the plaintiff's evidence that he fell three times; on the first occasion "almost straight away", and on the second occasion, after "about 50 metres". And it was on the third occasion that he fell that he sustained his injuries. His account of the incident is in the following terms (exhibit D at [44]-[46]): The last time that I got up on the board I didn't even have time to properly position my feet on the board before I came off. The board wasn't straight at the time I fell. The boat hadn't yet hit full speed when the accident happened. I think it had moved about 15 metres from its start position when I came off the board. The next thing that I remember is falling off the wake-skate. I fell forwards. I can't remember whether I let go of the rope as I fell, but I can remember getting a breath of air. I don't recall going up in the air before I hit the water. My feet did leave the board and I went forward. Then I hit the water, head first. 46The plaintiff's memory in the moments following the fall is understandably poor. He said that he did not know how deep he went below the water, whether he hit the bottom, or how long he was lying in the water before help arrived (exhibit D at [49]-[50], [52]). He said his first memory after falling was trying unsuccessfully to roll over, before being turned over in the water by his friend, Mr Woodford (exhibit D at [52], [54]). 47He recalled that there were a number of people in the water assisting him, and that they were standing. He said the person who was near his head had water up to, about, his belly button (exhibit D [57]-[58]). He also gave evidence that when he was rolled over, he could see that he was "very close to the channel markers", but could not say whether he was "just inside the channel or just outside it" (exhibit D at [56]). 48Police interviewed the plaintiff on 26th March 2008. Exhibit E is a transcript of the recording. His account with respect to the distance over which he travelled on the wakeskate before his third fall differs from the account given in exhibit D. In the course of the police interview, Mr Hume suggested that prior to the fall causing his injuries he was up on the board for "at least 100 metres". Counsel for the defendant, Mr Parker SC, crossed examined the plaintiff about these varying accounts. Mr Hume's oral testimony was that while he could not recall the distance he had travelled, "it would be the longer distance rather than the shorter distance, because 15 metres would be barely enough to get you out of the water in wake skating" (35.35T). This must be correct. 49As I have said, Mr Woodford was the observer on the boat at the time of the accident. The observer's chair faces the skater. His role includes reporting any difficulty experienced by the skater to the driver (exhibit 7A at p7). Mr Woodford's evidence in chief is recorded in two statements, one of which was dated 17th April 2011 and marked exhibit 4A, while the other was undated and marked as exhibit 4B. As Mr Woodford did not have a boating licence (exhibit 4B at [3]-[4], [8]), but nothing turns on this. 50Mr Woodford said before the plaintiff's third fall, the defendant had throttled up to a speed of about fifteen to twenty knots. As I have said, this is cruising speed. After getting up onto the wakeboard for "about 5 seconds", the plaintiff suddenly fell forward (exhibit 4A at [2]). Mr Woodford then informed the defendant that the plaintiff had fallen off, at which point the defendant circled the boat back to pick him up. When the boat returned to the site of the fall, Mr Woodford realised the plaintiff was still lying face down in the water. He then entered the water to assist him. On Mr Woodford's account, the water depth was "above [his] head height", and he said he recalled having to push off the bottom to try to support the plaintiff (exhibit 4A at [5]). He also said that he then "moved over to the shallower water so that [he] could stand up on the mud flats or sandbars", and that this occurred "before any other persons turned up to assist" (exhibit 4A at [6]-[7]). 51Mr Woodford was cross-examined by Dr Morrison SC about the precise distance over which he had moved with the plaintiff before being able to stand. He agreed that he had not moved "any significant distance"(188.45-189.5T). He also agreed the accident occurred "very close to the sandbar", and that the sandbar was at least at waist depth a metre or two from where the plaintiff fell (190.35T). Mr Woodford however was of the belief that they were inside the channel marker when the accident happened (exhibit 4A at [9]; 189.15T). Whilst maintaining his belief that the accident happened "in the channel", he agreed that it happened "very close to the sandbar". He agreed with the cross-examiner that "nowhere [in the channel was] shallower than 3 metres". He seemed to accept that if that was so, the accident could not have occurred in the channel (190.5 - .20T). 52Before me he maintained that he entered the water by diving, suggesting deep water. But in exhibit 4A he had said he "jumped in", suggesting shallower water. In the end I understood him to accept that he had jumped, not dived (193.5T). 53I permitted some further examination in chief by reference to the aerial photograph attached to exhibit 4A. Mr. Woodford, for the purpose of his statement, marked in pen a rough straight line and a circle. The circle appears above a white dot, which is the depiction of the marker buoy in the photograph. It may be taken to indicate the area around the marker buoy. He said that the circle depicts "roughly where the accident happened", and the line "where the boat was travelling" (195.20 - .30T). In further cross-examination, he agreed that if the plaintiff fell off somewhere in the vicinity of the green channel buoy in accordance with his markings "it may well have been out of the channel" (196.15T). 54In a sketch prepared by Mr. Woodford dated 24th November 2007, admitted into evidence without objection as part of exhibit "X" (it bears the pagination "88"), Mr. Woodford depicted himself and the plaintiff in the water as other boats arrived - no other persons are shown as being in the water - at a point to the west of the channel marker. Moreover, in his statement to the police on 26th November 2007, also forming part of exhibit "X" and paginated 85-86, Mr. Woodford said at [12]: We really didn't move once Marto fell, we just stayed there until the emergency services arrived. We could have drifted but we were pretty much in the same spot. 55The defendant, Mr Patterson, gave two written statements, dated 5th February 2008 and 30th June 2011. These were marked as exhibits 2 and 3 respectively. The defendant's account of the events leading up to the incident was in similar terms to that given by the plaintiff. The defendant said that he collected the plaintiff from the Chinderah boat ramp at approximately 2:00 pm on the day of the incident, and that he, the plaintiff and Mr Woodford had set out into the channel, with the plaintiff in tow riding a wakeboard. The plaintiff wakeboarded for a short time (approximately 20 minutes), falling occasionally, before switching to a wakeskate (exhibit 2 at [13]-[14]). 56With respect to the sequence of events surrounding the fall causing the plaintiff's injuries, the defendant's evidence-in-chief is similar to that given by Mr Woodford in chief. Mr Patterson said that the plaintiff was attempting a 'deep water start' while he (the defendant) throttled the boat up to a speed of fifteen to twenty knots, moving downstream (exhibit 2 at [15]-[16], exhibit 3 at [2]). As the defendant was driving the boat and was facing away from the plaintiff, he did not see the accident occur, but was alerted to the fall by Mr Woodford. The defendant turned the boat around and when the boat arrived by the plaintiff's side, the defendant saw Mr Hume "face down in the water, panicking" (exhibit 2 at [17]). Mr Woodford then entered the water. In exhibit 2 he said Mr Woodford "dove in" and in exhibit 3, he "jumped in". It was Mr Patterson's evidence that Mr Woodford "could not touch the bottom of the river" (exhibit 3 at [4]). After the plaintiff reported an inability to feel any part of his body, Mr Patterson called an ambulance using his mobile telephone. He stayed on the phone, in the boat, until the ambulance arrived (exhibit 2 at [19]). The defendant said that whilst he and Mr Woodford assisted the plaintiff, the defendant from the boat, they drifted over towards the sand bank and eventually Mr Woodford was able to stand up in the shallower water once they were out of the channel (exhibit 3 at [5]). At this time, after the ambulance had been called and the trio had drifted to the sand bar, a person in another boat arrived at the scene and also entered the water, helping Mr Woodford keep the plaintiff stable in the water (exhibit 2 at [20]; exhibit 3 at [6]). 57Mr Patterson gave evidence about the location of the boat at the time of the incident. In his second written statement he indicated that he was "clearly to the right of the channel marker" and "far from the edge of the channel" although he was "not... sure how far inside the channel marker" he was (exhibit 3, page 2). The defendant reiterated the substance of this evidence in cross-examination. He said he was "on the eastern side of the buoy" (160.45T) and "just to the left of the centre of the channel" (160.50T). 58Under cross-examination, Mr. Patterson initially remained adamant that the accident happened whilst he was navigating in the channel just to the left of its centre (160.45 - 161.5T). He didn't observe any shallow areas in the channel nor did he observe any "debris or wreckage or hard object" (155.25 - .30T), submerged or otherwise, I interpolate. He agreed that his first statement, exhibit 2, made no reference to the plaintiff drifting to shallower water after Mr. Woodford commenced to rescue him (157.5T). Nor does this statement contain any suggestion that Mr. Woodford swam Mr. Hume across to the sandbank (158.25T). He agreed that in a sketch prepared by him on 24th November 2007 he drew the boats involved in Mr. Hume's rescue "clustered around in the vicinity of the channel marker" (170.10T; exhibit P). He denied that the accident happened over the edge of the sandbank or that Mr. Woodford was able to stand when he entered the water to assist the plaintiff (177.15 - .25T). 59Mr. Patterson was cross-examined about his conversation on the telephone with the ambulance operator. He recalled some of the details but not all of them (179.10 - 181.35T). I am satisfied that the transcript, which was admitted as exhibit O, is accurate. 60He told the operator that the accident happened "just about five minutes ago". I would not take this literally as the call was logged close to 2:15pm. It indicates the passing of a short period of time only. At that time, the defendant reported that there were two people in the water supporting the plaintiff. From this I infer that the call took place after Mr. James Myers, another boater, whose evidence is referred to below, arrived on the scene. The defendant said, "There are two blokes standing and holding him up about waist deep". The defendant confirmed that the persons supporting the plaintiff were able to stand up. A little later he said, "We've got half a dozen people here supporting him". The transcript contradicts the statement that other rescuers only arrived after the call to the ambulance. I accept it as reliable as to its details. 61Early in the conversation, the defendant said to the operator: I don't think we can get him across the river because we are on a sandbank away from the other side of the river ... He reported "we are at least 100 metres across the river ... in the middle of the river". And a little later the following exchange occurred: Operator: Just get somebody to support him but try not to move him as well. Is the water running anywhere or is he going anywhere? [The Defendant]: No we are still sitting in the same spot. We are on the sandbar. 62The defendant was recalled to give further evidence on 25th March 2013. Again he was adamant that he did not go outside the channel. He denied the suggestion going outside the channel is "exactly what happened on [the] day" (341.10T). 63Notwithstanding his adamantine answers, at 175.35 - 50T he became unable to say where he was in relation to the channel marker at the time the accident occurred, although he rejected the suggestion that "it must have happened outside the channel marker" (176.20T). 64Mr James Myers gave a sworn statement dated 20th October 2011 with an annexed colour aerial map of the location of the incident marked with two coloured "X" symbols. Together these were marked exhibit M. A second evidentiary statement of 25 November 2007, taken by the police seven days after the incident occurred, was also tendered as exhibit N. James Myers (whom I will refer to as Mr J Myers so as to distinguish him from his son Adam, whom I will refer to below as Mr A Myers) was on board the first boat that came to assist the plaintiff and his friends at the scene. His son, Mr A Myers, and his son's friend Geoffrey Harrison were also in the boat. They were aged twelve and thirteen respectively. 65Mr J Myers says he saw the boat towing the plaintiff approaching the bend at Chinderah prior to the accident, and formed the impression "that the driver was cutting the bend too close" (exhibit M at [6]). I repeat that the river turns from the north east to north at Chinderah Bay. Mr J Myers did not see the plaintiff fall from his wakeskate because he was manoeuvring his vessel into the Chinderah boat ramp - and therefore facing in the opposite direction - when the fall occurred. He says that when he was alerted to the fall by his son, and noticed that the plaintiff was not moving in the water, he "immediately turned [his] boat around and accelerated" toward the scene, arriving there "no more than a minute" later (exhibit M at [6], [9], [12]). 66He says when he arrived at the scene of the fall he handed over control of the boat to his son and jumped in the water. His evidence is that the water was only "crotch to waist deep" on him, and "probably chest deep or lower" on Mr Woodford (125.50; 139.30T). He is 186cm tall (exhibit M at [13]). He also said (exhibit M at [17]): The whole area in the vicinity of where we were was shallow. It never got above waist deep. 67When questioned about whether the plaintiff's position in the water had changed during the time from when he first saw the plaintiff in the water to when he jumped in to assist, Mr J Myers denied that the plaintiff had moved in the water or had been moved by anybody else (125.20-.35T). 68As I have said, Mr J Myers' statement includes a colour aerial map of the location of the accident. On this map are marked two "X" symbols, one in yellow indicating Mr J Myers' impression of the location of the boat in which he was travelling when he was alerted to the accident, and another in purple indicating the position on the river where Mr J Myers says the plaintiff fell, and at which Mr J Myers entered the water to help. The latter symbol places the location of the incident on the eastern edge of the sandbar. However under cross-examination Mr J Myers accepted that he could not identify the channel marker on the map and therefore could not say whether the position indicated as the site of the fall was inside or outside the marker (130.25T). 69Mr A Myers, as I have noted above, is the son of Mr J Myers, and was in the boat with his father and a friend, Mr Harrison (whose evidence I will refer to below) when the plaintiff fell from his wakeskate. Mr A Myers was born on 18th April 1995, was twelve years old at the time of the incident and seventeen years old when he gave evidence at trial. His evidentiary statement of 13th January 2012 was marked exhibit G while his police statement of 25th November 2007 was marked exhibit H. 70Mr A Myers noticed the boat towing the plaintiff approaching from approximately 60 metres away. In his statement he gave the following account (exhibit G at [5] - [6], [8] - [9]) I saw the skier do some turns in the wake [and] he then went outside the wake and came back in. When he went over the wake he got airborne and lost control, fell forward and hit the water at a fairly steep angle. From where we were I could see the sandbar. The boat appeared to be on or near the edge of the sandbar. When he jumped off the wake the front of his board caught [an] edge and he tipped forward quickly. He let go of the rope before he hit the water. When he hit the water he went in head first with his hands in an upward position but only as far as the side of his head. He went into the water and suddenly stopped with his feet left sticking out of the water. He then floated to the surface and floated face down. 71Mr A Myers said that the defendant then turned the boat around and returned to the location of the fall. He says that the observer, Mr Woodford: ...rushed to the back of the boat and jumped onto the duckboard. He sat down on the duckboard and tried to grab the person in the water. He then pushed himself off the duckboard and slid into the water and grabbed the skier around the chest and flipped him over. (Exhibit G at [10]). 72In cross examination Mr A Myers agreed that he had mistakenly referred to the plaintiff as a "skier" and that it was more accurate to describe him as a "skater". However he rejected any suggestion he may have been mistaken about whether the plaintiff had gone outside of the boats wake and then come back in (76.10T). He gave evidence that both the plaintiff and the towboat were "on the plane" and that the plaintiff then got airborne, about two feet off the water, at which point he fell at an angle of about 35 to 40 degrees (74.40-76.5T). Mr A Myers disagreed with the suggestion that he may have been mistaken about the boat from which the plaintiff was being towed having a duckboard (81.20T). He said he could not remember seeing the navigation marker (77.45T; 82.10T). 73In his statement, Mr A Myers said the water was waist deep on the bodies of both Mr Woodford and Mr J Myers (exhibit G at [13]). When questioned about these matters, Mr A Myers confirmed that the water was "probably just above [Mr Woodford's] waist", and "waist deep" on his father (68.25-30T). Mr A Myers also rejected the suggestion that the plaintiff's position had moved more than one or two metres from the time he fell to the time his fathers boat arrived, or that Mr Woodford moved the plaintiff over to the sandbar (68.35-40). 74Mr Geoffrey Harrison, as I have said, was also on board Mr J Myers' boat. He was born on 24th February 1994. He saw a wake boarder coming towards him on the river. He says the rider fell from his board, went three feet in the air, hit the water and then lay face down floating in the water, not moving (exhibit J at [5]-[7]). 75In exhibit K, a statement made on 25th November 2007, he put the sequence of events differently (at paragraph [6]). The wakeboarder "getting air" preceded him falling. In cross-examination (at 108.10 - .20T) he sought to clarify his evidence by explaining that the wakeboarder crossed to the outside of the wake and "as he was coming back he got air". Then he fell. He said he entered the water at an angle of about 45 degrees (109.12T). In his statement he described the injured person as a wakeboarder. He knew the difference between a wakeboard and a wakeskate, but at the time of the accident he assumed that the plaintiff was on a wakeboard. 76Mr. Harrison said that when he got into the river to help with the rescue the water "was up to my belly button" (exhibit K at [9]). He is now aged eighteen and six feet and four inches tall. At age thirteen was shorter. 77In chief, Mr Harrison marked exhibit L with an "X" symbol to indicate where the accident happened. The symbol puts the location of the accident west of the marker, well over the sandbar, out from the boat ramp. This puts the scene of the accident in a place similar to that indicated by the mark made by him on exhibit "1", an out of court representation by him (112.5-20T), and in a similar location to Mr J Myers mark. 78Mr. Harrison was clearly confused about some details. In evidence, as I understood him, he indicated the water was deeper than he had suggested in his statement (95.20 - 91.20T). Moreover he had the plaintiff travelling upstream (south), not downstream (north), immediately before the accident (114.50 - 115.17T). This is clearly incorrect. 79It was suggested to him that he may have been mistaken as to the person he was observing, which proposition he rejected: (108.45T). 80Mr. A. Myers and Mr. Harrison were, as I have said, twelve and thirteen years old respectively at the time of the accident. Because of their youth and the effluxion of time since the accident, I am of the view they are clearly wrong in some respects. They are clearly wrong about the plaintiff being airborne immediately prior to his fall. Neither the plaintiff nor Mr. Woodford say that, and I think in this respect their account is more likely to be reliable. Obviously, they were directly involved in the action and the boys were some distance away. Moreover, the plaintiff was a novice at wakeskating and there is no suggestion he had progressed to tricks or stunts on his third attempt on his first day of trying a new sport. As I have said, Mr. Harrison clearly has the direction of travel wrong. These considerations, however, do not lead me to conclude I should reject the whole of the evidence of both of them. 81The Plaintiff's mother Mrs. Barbara Hume was called to give evidence, and, subject to some objections to part of paragraph 12, was admitted into evidence as exhibit F. She was not cross-examined. The significance of her evidence is that when stroking the plaintiff's head in hospital about a week after the accident she noticed river sand and grit in his hair and scalp. She described it as "not fine beach sand". As a mother her concern was about hygiene, as it occurred to her that her son's hair had not been washed at all in hospital. She raised this with one of the nurses who explained that they had been unable to shower the plaintiff until a surgical scar on his neck started to heal. I confess to having been initially sceptical about this evidence, not because I doubted Mrs. Hume's sincerity, but because I wondered about her ability to discern between river and beach sand. But her evidence fits in with the agreement between the biomechanical engineers as to the mechanism of injury and their evidence about a sandy river bottom "giving" and "capturing" the skull of a person colliding with it in the manner hypothesised by them in this case. As I say her testimony was not challenged. 82Mr. Scott Nipperess gave evidence in the defendant's case. He had been in the boat at the time the plaintiff joined it at the Chinderah Boat Ramp. Mr. Nipperess and two others disembarked to go for lunch. Mr. Nipperess said when he became aware of the accident he swam out to where the plaintiff was being supported and found that it was in water so deep that he could not touch the bottom (exhibit 5 at [14] - [17]). His evidence is that he assisted swimming the plaintiff over "to the sandbank so that we could at least stand up". 83The difficulty with this evidence is that he says (exhibit 5 at [11]) that he was made aware of the incident by the ambulance arriving at the boat ramp car park. By then, on any version, those assisting the plaintiff were standing in shallow water (199.40 - 200.15T). I am not able to accept his evidence. Where in the river did the accident occur? 84The question may be refined as whether I am persuaded on the balance of probabilities that the accident happened outside the channel in relatively shallow water over the sandbank. To answer this question favourably to the plaintiff, I would need to be satisfied, as Dixon CJ remarked in Jones v Dunkel (1959) 101 CLR 298 at 304, to the following standard: In an action of negligence for death or personal injuries the plaintiff must fail unless he offers evidence supporting some positive inference implying negligence and it must be an inference which arises as an affirmative conclusion from the circumstances proved in evidence and one which they establish to the reasonable satisfaction of a judicial mind. It is true that "you need only circumstances raising a more probable inference in favour of what is alleged". But "they must do more than give rise to conflicting inferences of equal degree of probability so that the choice between them is mere matter of conjecture". [Citation omitted]. 85The defendant submitted that I could not be so affirmatively satisfied that the accident happened outside the channel because: (a)According to exhibit A, the channel, even if only at its western extremity, is as shallow as 2 metres in depth; and (b) The biomechanical evidence is to the effect the injury could have occurred in a depth greater than 2 metres. 86I have already said at [39] and [42] that I prefer the evidence of the depth readings taken by Mr. Cormack in March 2008, and on the view, to exhibit A. On this basis, the depth drops from 2 metres, 30 metres west of the marker, to a range of 1.1 to 1.3 metres, 40 metres the west of the marker. Nowhere in the channel in the vicinity of the marker is less than 3 metres in depth. At this depth a catastrophic spinal cord injury caused by the fracture of C6 is highly unlikely to occur, on the assumptions expressed at [18] and [20]. 87I find that each of the assumptions made by the biomechanical engineers has been made good by the evidence. As I have said, I reject that part of the evidence of Mr. A. Myers and Mr. Harrison that the plaintiff fell from an elevated height because he was airborne when re-crossing the wake. Rather, I find that he remained inside the wake; that the fall occurred soon after he had completed his deep water start; that he was standing erect; and that he pitched forward as though diving when both he and the tow boat were on the plane at a cruising speed of 15 to 20 knots per hour. I accept the evidence of Mr. Harrison that he entered the water at about a 45-degree angle. This is similar to the assessment of Mr A Myers. I have already said, at [18], that the plaintiff was 183 centimetres tall and weighed 100 kilograms. 88I reject the submerged object hypothesis. Whilst it remains a theoretical possibility, there is simply no evidence giving it any credence whether from the defendant or anyone else. Moreover, it does not tally with Mrs Hume's evidence about the sand in her son's hair, which I accept. As I said at [81] this evidence fits in with the agreed biomechanical evidence on the probable mechanism of injury. (See [90] below.) 89Further, despite discounting some of Mr. A. Myers evidence because of his youth as at November 2007, I am satisfied that his somewhat graphic description of "landing head first into the sandbar" (exhibit H [6]) is the type of detail likely to stick in the mind, especially if one adds the further consideration that the plaintiff's feet were left sticking out of the water (exhibit "G" [9]). He repeated this in his oral testimony (77.15T). Despite a searching cross-examination about various details of the events leading up to the accident, it was put in general terms only that Mr. A. Myer was "substantially mistaken" (85.5T). He was not specifically challenged about seeing the plaintiff's feet sticking out of the water except at 77.12T, when it was put "then you saw him with his feet sticking out, is that right?" - my emphasis - to which the witness responded "yes". But I would not dissociate the evidence of the plaintiff's feet protruding from the water from the preceding statement of the plaintiff's head connecting with the sandbar. The evidence spoke of a single event, not a strike followed by a rebound. 90This evidence, which I accept, to my mind, and it is largely a matter of impression, supports the case that the plaintiff fell in water of between 1.1 and 1.3 metres in depth. At such a depth, the risk of catastrophic injury to the cervical spine is between "high" and "substantial" ([20], above). And that joint opinion of the biomechanical engineers provides strong circumstantial evidence supporting the plaintiff's case that he fell in shallow water. So too does Professor Yeo's evidence recounted at [16] above, even if expressed in terms of some generality. 91Mr. J. Myer's evidence of the water being "shallow" and "about waist deep", which I accept, is also consistent with this conclusion. This is supported by Mr. Harrison's police statement (exhibit K) and by Mr. A. Myer's police statement (exhibit H). These estimates, given a week after the accident, for that reason, are likely to be reliable. 92My preference for this body of evidence means that I reject that part of the evidence of Mr. Patterson, Mr. Woodford and Mr. Nipperess suggesting the accident happened in deep water. The evidence of Mr. Patterson and Mr. Woodford was to the effect that the accident occurred in the channel. Mr. Nipperess did not mention the channel but, inferentially, that is what he meant. 93The evidence of Mr. Nipperess can be put to one side safely. His evidence is so inconsistent with all of the other evidence for the reason given at [83] that he must be wrong. 94As I have explained above at [51] - [54], Mr. Woodford made significant "concessions" in cross-examination. I was left with the impression that he effectively accepted that the plaintiff fell outside of the channel "very close to the sandbar". His contemporaneous accounts recorded at [54], and as depicted in the sketch dated 24th November 2007 and in his police statement of 26th November 2007, support the conclusion that, at least on the balance of probabilities, the accident happened over the sandbar in relatively shallow water. I appreciate that the sketch depicts the aftermath of the accident, and locates it west of, but close to, the marker buoy. I have set out my findings about depth above (at [38]-[39]). One needs to travel 20 metres to the west of the marker before the depth falls below 3 metres. At that point, it is either unlikely or highly unlikely that the plaintiff could have broken his neck. It needs to be borne in mind that the sketch is just that, a sketch. It is not drawn to scale. The statement "[w]e really didn't move once Marto fell", taken with the other evidence which I accept, supports the conclusion that the depth where "Marto fell" was such that those assisting the plaintiff were comfortably able to stand. This suggests to me a depth of no more than 1.1 to 1.3 metres, probably at the lower end of that range. Understood in this way, Mr. Woodford's evidence in fact supports the conclusion for which the plaintiff contends. 95I appreciate that this puts the place where the plaintiff fell 40m west of the marker and the plaintiff remembers being very close to the marker while waiting for the ambulance. "Very close" is a relative term and I am not satisfied, given what he had just gone through that his impression about this displaces the accounts of the other witnesses I have accepted. 96I turn now to the evidence of the defendant. I should say that Mr. Patterson, making every allowance for his comparative youth, was often a very defensive witness. At times he was combative and frequently suspicious of the cross-examiner's motives. He said he did not understand questions, which, at least at times, I considered straightforward. Perhaps these aspects of demeanour are understandable. After all, as I have said, he is a young man, and his conduct on the day was being thoroughly scrutinised. His strong and precise evidence that he was navigating the boat to the left of the centre of the channel did not survive cross-examination, as I have recounted at [63]. In the end he was unable to say where the vessel was in relation to the channel marker at the time the accident occurred, notwithstanding that he rejected any suggestion that he was outside the channel. 97Mr. Patterson's evidence about where he was in the channel at the time the plaintiff was injured is so far out of step with the other evidence I find acceptable that I must reject it. 98The version that the boat was just to the left of the middle of the channel at the time the plaintiff fell did not accord with the probabilities. As I have found at [38], around it's middle, the channel is 8.2 metres deep. The channel is about 75 metres wide, and accordingly, a course just to the left of it would be between, say, 45 and 50 metres from the eastern shore, which, on anyone's version, if Mr Patterson is correct, would have been substantially closer to the location of the accident than the shallow water over the sandbar where the plaintiff and those assisting him waited for the ambulance. That place itself would be about 75 metres west of the course the defendant says he was following. It would have been necessary to "swim" the plaintiff there from the deep water. But it would have been much easier to take him to the eastern bank than out to the sandbar. Absent a large submerged object, the plaintiff's injury could not have occurred in eight metres of water. As I have already found there is no foundation in the evidence at all to support that hypothesis (even accepting, as I have, that it is at least theoretically possible). It is not possible to overcome these logical difficulties simply by postulating that perhaps the defendant was somewhat out and that he was probably following a course at the western extremity of the channel. This requires me to speculate, in effect to guess, in the absence of any evidence supporting that theory. I accept that the onus of proof lies upon the plaintiff and never shifts. Further, as I have already found, even at its extremity, the channel was between 3 and 5.3 metres deep. It is highly unlikely that the plaintiff's injury would have occurred in water of that depth, once again absent the submerged object hypothesis. 99Another current running through the defendant's case is that the plaintiff fell in relatively deep water and drifted to shallow water whilst waiting for the ambulance to arrive. Assuming in the defendant's favour for the purpose of the argument that the relatively deep water was within the channel, this involves the hypothesis that the plaintiff effectively drifted due west to the shallow water over the sandbar. Such a hypothesis is inconsistent with the evidence of Mr. Sutherland, which in this regard, as I have said above (at [41]), was that the prevailing "drift" was in a south-easterly direction (371.5T; 372.20T). Despite the benefit of an adjournment for that purpose, the defendant did not call in the evidence to contradict Mr. Sutherland's evidence, and I accept it. 100The defendant submitted that I could not rely upon the evidence of Professor Yeo to work out the location of the accident because the opinions expressed by him, which I have recorded, went beyond his specialised knowledge. It was further argued that without his evidence the opinions of the biomechanical engineers were worthless because they depended in part upon the availability of reliable medical information. The purport of this argument, if accepted, was that it was impossible to determine where - either inside or outside the channel - the plaintiff's accident occurred. This did not depend upon acceptance of the submerged object hypothesis because a body of evidence, specifically exhibit A, supported the proposition that the depth of the channel in places was as shallow as two metres and at that depth it was possible for the plaintiff to suffer his catastrophic injury. 101It is true enough that Professor Yeo did not examine the original radiographic material, but at the same time there was no serious dispute about the nature of the plaintiff's injury. I did not understand it to be disputed that the plaintiff suffered a catastrophic spinal cord injury because the fracturing C6 vertebrae compressed the spinal cord. I did not understand it to be disputed that the likely mechanism of this fracture was the application of a significant compressive force through his head when his neck was in a position of significant disadvantage because it was bent. I did not understand it to be disputed that the origin of such a force was the head striking a more or less immovable object at speed. A submerged object or the bottom would equally suffice. 102I accept, as I have recorded above, that Professor Yeo has no specialised knowledge in relation to the injurious incidents of wakeskating. He does have relevant expertise acquired through experience with diving injuries and, as I have said, the plaintiff's injury has much in common with injuries of that type. Moreover, in my judgment once it is known that the plaintiff suffered a broken neck, and the aetiology of that injury is identified in the general terms I have described at [100], the mechanical engineers are well qualified to express opinions about the possible mechanisms by which it may be caused. 103In determining the likely location of the accident it is not appropriate to consider the expert evidence in isolation from its context amongst the whole of the evidence, both direct and circumstantial. The finding I have made is based upon my consideration of all of the circumstances established by the evidence to my satisfaction by application of the principle expressed by Dixon CJ in Jones v Dunkel. 104I am comfortably satisfied on the balance of probabilities that the plaintiff suffered catastrophic injury when he fell whilst wakeskating over, or close to, the sandbar to the west of the channel at Chinderah Bay in shallow water of approximately 1.1 metre in depth. This is what I mean later when I use the expression "over or close to the sandbar". The question of negligence 105As I have previously indicated, it is not contested that the defendant boat driver owes the plaintiff wakeskater a duty of care recognised by the law of negligence, the content of which is to exercise reasonable care for the safety of the plaintiff in the conduct of the activity: Rootes v Shelton (1967) 116 CLR 383. 106The key question is whether in the circumstances as I have found them the defendant is guilty of negligence. That question is to be determined by reference to the provisions of Part 1A Civil Liability Act 2002 (NSW), and in particular sections 5B - 5E. 107The central provision concerning the question of breach, of course, is s.5B, concerned with negligence that consists of the failure to take precautions against a risk of harm. 108The parties essentially agree that the relevant risk of harm for the purpose of s.5B in the present case is the risk of the plaintiff suffering appreciable, rather than transient, physical injury from falling and colliding with the bottom of the river: defendant's submissions, page 13 [65]; plaintiff's submissions, page 13 [43]. 109The relevant precaution contended for was navigating the towboat in water known to be deep enough for the purpose of minimising the risk of harm. On the facts now known, the precaution could have been satisfied by navigating in, or within about 20 metres (to the west) of, the channel. From his evidence the defendant may not have known the depth outside the channel and might have expected it to be variable. Accordingly the relevant precaution may be taken to call for navigation within the channel. 110I bear in mind that it is necessary to consider the essential requirements for a finding of breach established by s.5B(1) prospectively, as though the plaintiff's accident had not occurred. It would be erroneous in a fundamental way to employ the benefit of hindsight. Moreover, the standard of care is the standard of a reasonable person in the position of the defendant: Imbree v McNeilly [2008] HCA 40; 236 CLR 510. 111In the present case the standard of care must be formulated by reference to the attributes of a reasonable recreational boat driver engaged in wakeskating. The usual knowledge of spinal specialists or even biomechanical engineers cannot set this standard: Dovuro Pty Ltd v Wilkins [2003] HCA 51; 215 CLR 317 at 369 [163] per Hayne and Callinan JJ. It may also be debatable whether the expertise of a professional like Mr. Ellison is attributable to the reasonable recreational participant. However that may be, in light of the evidence of Mr. Ellilson at 402.45 - 403.5T, and of the defendant at 340.35 - 341.10T, it may be accepted that the identified risk of harm was foreseeable because the defendant knew that there was shallow water over the sandbar and that there is the potential for injury to a wakeskater who falls and hits the sandbar if the boat is navigated over, or close to, it. It may be that, given Mr. Ellison's evidence, a reasonable recreational boat driver would not expect catastrophic injury to be suffered by a person hitting the bottom. But weighed objectively the relevant risk of harm is not insignificant when one considers the degree of likelihood of a falling skater hitting the bottom and suffering appreciable not transient injury. Were it permissible, as it is not, to have regard to the usual knowledge of the experts in evaluating this factor clearly, in some circumstances anyway, catastrophic injury is on the cards. 112By reference to the relevant matters set out in s.5B(2) I am satisfied that in the circumstances a reasonable recreational boat driver would have taken the precaution of conducting his part of the activity of wakeskating, i.e. driving the tow boat, wholly within the marked channel. In my judgment, the probability that the harm would materialise if the precaution were not observed is relatively high. The defendant's evidence acknowledged that outside the channel the water could be shallow and the wakeskater could fall and hurt himself (340.35 - 341.12T). The facts in the present case clearly indicate that the harm suffered could be very serious indeed. But eschewing hindsight, it is implicit in Mr. Ellison's view that 1.5 metres is a safe depth, that less is unsafe. The defendant accepted so much: submissions page 13[64] - 14[67]. The burden of taking precautions to avoid the risk was slight, and involved no more than remaining within the channel. One may well accept the high social utility of participation in healthy, recreational sporting events. But the risk of harm in this case was not created by participation in the sport of wakeskating per se; rather conducting the activity in shallow water - or at least water of unknown and variable depth - over, or close to, the sandbar, created it. 113In my judgment the defendant was negligent in failing to navigate the boat wholly within the channel whilst towing the plaintiff. 114None of the principles referred to in s.5C of the Act have any impact on the outcome of the present case. Causation 115The onus of proving every fact necessary to establish that the negligence of the defendant caused his injuries lies, and remains, with the plaintiff: s.5E Civil Liability Act 2002. 116By s.5D the establishment of legal causation depends upon proof that the negligence of the defendant was a necessary condition of the occurrence of the injury suffered by the plaintiff, and that it is appropriate for the scope of the defendant's liability to extend to that injury: s.5D(1). In the circumstances of the present case, no question arises under s.5D(2) or 5D(3). 117The defendant did not contest causation seriously, if the elements of breach were established (submissions page 18 [89]). But it is appropriate that I record my findings. 118The plaintiff fell and struck his head on the sandbar at a depth of about 1.1 metres, and this mechanism of injury subjected his cervical spine to axial compression. The plaintiff's injury would not have occurred but for the defendant's conduct in navigating the boat over or close to the sandbar. To put it another way, had the defendant remained inside the channel where the depth was at least 3 metres, I am satisfied on the balance of probabilities that the plaintiff's injury would not have been sustained. At that depth on the primary facts I have found the risk of catastrophic injury was highly unlikely to materialise and this is a material circumstance. Unlike breach, questions of causation are determined with the benefit of hindsight. The purpose of the inquiry is to ascertain what happened and why. Even had the boat been navigated at the western extremity of the channel, the depth is such that no appreciable injury would have occurred. I am satisfied on the balance of probabilities that but for the failure of the defendant to take the precaution of remaining in the channel, the plaintiff's injury would not have occurred. 119So far as the scope of the defendant's liability is concerned, a unanimous High Court of Australia in Wallace v Kam [2013] HCA 19; 87 ALJR 648 at [22] said the following: In a case falling within an established class, the normative question posed by s 5D(1)(b) is properly answered by a court through the application of precedent. Section 5D guides but does not displace common law methodology. The common law method is that a policy choice once made is maintained unless confronted and overruled. 120 Their Honours went on to explain at [26] that: .... the scope of liability for the consequences of negligence is often coextensive with the content of the duty of the negligent party that has been breached. That is because the policy of the law in imposing the duty on the negligent party will ordinarily be furthered by holding the negligent party liable for all harm that occurs in fact if that harm would not have occurred but for breach of that duty and if the harm was of a kind the risk of which it was the duty of the negligent party to use reasonable care and skill to avoid. 121Rootes v Shelton, and to some extent Wyong Shire Council v Shirt (1980) 146 CLR 40 at 47 - 48, establish that the present case falls within an established category of liability. I have held that the harm suffered by the plaintiff would not have occurred but for the defendant's breach in navigating the vessel outside the channel in shallow water over, or close to, the sandbar. The personal injury suffered by the plaintiff was of a kind, the risk of which it was the duty of the defendant to use reasonable care and skill to avoid. It is appropriate in my judgment that legal responsibility for the consequences of his breach of duty should be attributed to the defendant. Dangerous recreational activity 122The findings I have made so far are not sufficient to dispose of the case because the defendant invokes the provision of s.5L of the Civil Liability Act 2002, which are in the following terms: (1) A person (the defendant) is not liable in negligence for harm suffered by another person (the plaintiff) as a result of the materialisation of an obvious risk of a dangerous recreational activity engaged in by the plaintiff. (2) This section applies whether or not the plaintiff was aware of the risk. Obvious risk is defined by s.5F: (1) For the purposes of this Division, an obvious risk to a person who suffers harm is a risk that, in the circumstances, would have been obvious to a reasonable person in the position of that person. (2) Obvious risks include risks that are patent or a matter of common knowledge. (3) A risk of something occurring can be an obvious risk even though it has a low probability of occurring. (4) A risk can be an obvious risk even if the risk (or a condition or circumstance that gives rise to the risk) is not prominent, conspicuous or physically observable. And dangerous recreational activity is defined by s.5K dangerous recreational activity means a recreational activity that involves a significant risk of physical harm. obvious risk has the same meaning as it has in Division 4. recreational activity includes: (a) any sport (whether or not the sport is an organised activity), and (b) any pursuit or activity engaged in for enjoyment, relaxation or leisure, and (c) any pursuit or activity engaged in at a place (such as a beach, park or other public open space) where people ordinarily engage in sport or in any pursuit or activity for enjoyment, relaxation or leisure. 123There is now a significant body of jurisprudence concerning the meaning and operation of s.5L. It might be fairly said that s.5L is a signature provision of the reform of the law of negligence introduced by the enactment of the Civil Liability Amendment (Personal Responsibility) Act 2002 (NSW). 124In Fallas v Mourlas [2006] NSWCA 32; 65 NSWLR 418 at [123] Basten JA said: ...s.5L assumes there would otherwise be liability for negligence, and provides an immunity. The provision differs from the general law principle of voluntary assumption of risk because it does not require that the plaintiff had knowledge and appreciation of the riskwhich was accepted [citations omitted]. His Honour also held it was for the defendant to establish the elements of the immunity from liability: "accordingly, the principle that he or she who 'substantially affirms an issue must prove it' operates (citation omitted)" Fallas at 439 [122]. There were some differences amongst the Judges in Fallas, but all agreed with the reasons of Basten JA about where the onus lies. See also Lormine Pty Ltd v Xuereb [2006] NSWCA 200 at [31]. 125In Xuereb, Mason P pointed out that the question of whether a defence under s5L has been established must be "determined objectively and prospectively". The starting point must be determining the nature of the activity actually engaged in by the plaintiff, especially where, as here, it is of an ad hoc, as opposed to organised, type: Fallas at 426 [43] per Ipp JA; 432 [92] per Tobias JA; [144] - [148] per Basten JA. There is no doubt that the activity of wakeskating engaged in by the plaintiff was a recreational activity, being a sport as well as an activity engaged in for enjoyment and leisure, if not relaxation. The central and primary question, however, is whether it is a dangerous recreational activity. To my mind that central question cannot be considered without first determining the scope of the recreational activity at the appropriate level of specifity required by the passages from Fallas I have referred to. 126As a starting point, viewed objectively and prospectively, the plaintiff was proposing to engage in wakeskating in the relatively deep water in the channel on the eastern side of the Tweed River at Chinderah Bay. Bearing in mind that the onus lies upon the defendant, it was never suggested to the plaintiff that he and the defendant arranged that the activity would extend beyond the channel into the shallow water over, or close to, the sandbar. Indeed, the defendant's case strenuously eschewed this proposition. That I have rejected the defendant's evidence as to where he actually was at the time of the accident does not affect the assessment of the specific activity the plaintiff was engaging in. 127I regard it as significant that the plaintiff was not challenged about the nature of the activity in which he was engaged. By that I mean it was not put to the plaintiff that wakeskating in deepwater in the channel was a dangerous recreational activity because it involved a significant risk of physical harm. I appreciate by reference to s.5L(2), and Fallas at [123], that the plaintiff need not be aware of the obvious risk said to have materialised which results in his injury. However, the whole of the judgment of Ipp JA in Fallas, from 424 [30] to 427 [50], bears close consideration. As the question of whether an actitivity is a dangerous recreational activity must be assessed objectively and prospectively the inquiry is necessarily fact-sensitive. I accept, however, that a conclusion one way or another necessarily involves mixed questions of fact and law and for the reasons given by Gummow J in Dovuro at 339 [66] to 342 [71], it will be pointless to closely cross-examine a plaintiff about his perception or understanding of the question. Subjectively most people do not actually court danger even if a degree of risk adds to the exhilaration of a sport. For this reason, if asked, most would deny that recreations engaged in by them are dangerous. 128But as the determination of the question depends upon the consideration of all relevant circumstances including matters personal or subjective to the plaintiff such as competence, age and sobriety, it may be expected that the cross-examination will seek to elicit from the plaintiff relevant evidence tending to demonstrate dangerousness, and where appropriate challenge him or her about specific risks and the extent to which they may have been known or otherwise apparent. In the present case a purpose of the cross-examination of the plaintiff, consistently no doubt with the cross-examiner's instructions, was to pin the plaintiff down about the place where the activity was to be undertaken by restricting it to the channel. And it was not put to him that such an activity in that place involved any risk, significant or otherwise. It was certainly not suggested that the parties always intended to branch out into Chindarah Bay, west of the marker. 129In Fallas, at 424 [36] Ipp JA observed: Factors such as time, place, competence, age, sobriety, equipment and even the weather may make dangerous a recreational activity which would not otherwise involve a risk of harm (and the converse may be the case). 130In Falvo v Australian Oztag Sports Association [2006] NSWSC 17 at [28] - [31] his Honour pointed out that in the definition of dangerous recreational activity "significant" is to be construed as bearing not only on "risk" but also on the phrase "physical harm". His Honour said that weight had to be given to the word "dangerous" itself. 131The approach of Basten JA was to treat "significant" as qualifying the balance of the expression "risk of physical harm", clearly a composite idea (Fallas 440 [131]). The third member of that Court, Tobias JA at 432[90] - [92] agreed with aspects of the analysis of each of Ipp JA and Basten JA, however he preferred to approach "significant risk" as "one which has a real chance of materialising". His Honour also said: ... in determining whether the relevant recreational activity involves a significant risk of physical harm, one must identify that activity at a relatively detailed level of abstraction by including not only the particular conduct actually engaged in by the [plaintiff] but also the circumstances which provide the context in which that conduct occurs. 132All of these considerations were summed up pithily by Mason P in Xuereb, and I will repeat what his Honour said at [31]: The defendant bears the burden of proof in establishing a defence under s 5L. The question is to be determined objectively and prospectively. The standard lies somewhere between a trivial risk and one that is likely to occur. Significance is to be informed by the elements of both risk and physical harm. The characterisation must take place in the particular context in which the plaintiff places himself or herself. 133At least in the context of the commercial supply of recreational services, Mason P thought it relevant to consider how the defendant represents the activities it offers to its potential consumers. Similarly, in Echin v. Southern Tablelands Gliding Club [2013] NSWSC 516 at [112] Davies JA said: Whilst the determination of whether gliding is a dangerous recreational activity must be judged objectively, such a determination may be informed by views of persons with some knowledge of the sport. 134Bearing these considerations in mind, and in particular approaching the question of whether the activity actually engaged in by the plaintiff was a dangerous recreational activity at an appropriately detailed level of abstraction, I am not persuaded that the defendant has proved that the wakeskating engaged in by the plaintiff at the time of his accident was a dangerous recreational activity. 135The following circumstances have lead me to this conclusion: (ii)The activity was to be engaged in only in the relatively deep water of the channel; (iii)Unlike other variants of waterskiing, wakeskating is undertaken at a relatively slow speed; somewhat slower than wakeboarding; at about half the speed of waterskiing whether on one or two skis; and at a fraction of the speed of skiracing; (iv)The plaintiff was a novice but he had experience in other water sports including wakeboarding; (v)The evidence of Mr. Ellison that I have set out above at [10] - [14] does not support the idea that wakeskating is an activity involving a significant risk of physical harm even if one allows for the "inherent risks" which he identifies, some of which as I have said, are largely theoretical. On his evidence one would categorise wakeboarding in the deep water of the channel of the Tweed River at Chinderah Bay (being in excess of 1.5 metres deep) as a recreational activity enjoying a trivial risk of minor physical harm only. The risk of serious injury is remote; (vi)It may be permissible, taking an objective and prospective approach, to factor in the views of experts from other disciplines because the assessment of danger does not depend on the application of the universal standard of care. One would conclude from the evidence of the biomechanical engineers and of Professor Yeo that any risk of significant injury from striking the bottom in water of at least 3 metres in depth was one which was highly unlikely to materialise. Indeed according to the matters agreed on by the biomechanical engineers (see [18] above), the occurrence of the plaintiff's catastrophic injury depended upon the confluence of many factors including five which were specifically identified. Even at 1.5 metres or less in depth, so far as this may otherwise be relevant, it may be difficult to say that wakeskating involves a risk of injury through striking the bottom which had a real chance of materialising, to adopt Tobias JA's phrase. Especially when one bears in mind that "significant" informs both risk and harm. And considering the risk rating for catastrophic spinal injury provided by the biomechanical experts as set out at [20] above, it is relevant to bear in mind that the somewhat disparate risk factors identified actually need to be confluential before the risk materialises; (vii)I accept that a low risk of catastrophic injury may amount to a "significant risk of physical harm", but in my judgment the risk of the relevant causative factors combining to produce catastrophic injury if the plaintiff had fallen in identical circumstances in the channel was so low to justifiably be put to one side as not "significant": Falvo at [31] per Ipp JA; Fallas at 422[13]; [18]. 136It may well have been otherwise, of course, if the parties had decided to conduct the wakeskating over, or close to, the sandbar: see Fallas at 424 [36]. But that is the case of neither party. I have found that the defendant did drive outside the channel but I would infer that that occurred as a result of mere negligence, not by misconduct, nor in actively courting danger. 137Lest I be wrong in the conclusion I have expressed about the nature of the activity engaged in, it is necessary for me to consider whether the plaintiff's injury was the result of the materialisation of an obvious risk of the activity. The defendant still carries the onus. 138I will accept that "a significant risk that converts a recreational activity" into a dangerous one "may be entirely different ... from the risk ... that materialises": Fallas at 423[25] per Ipp JA; cf 445 [151] per Basten JA. 139It is clear from the definition in s.5F that in determining whether a risk is obvious, an objective approach must be taken. The risk is obvious if it would have been obvious to a reasonable person in the position of the plaintiff. It seems to me that the same level of specificity, or detailed level of abstraction, needs to be brought to bear in relation to the circumstances of the case for this purpose of determining whether the risk was obvious as was brought to bear in determining whether the risk was significant. As Basten JA said in Fallas at 445 [152], s.5L(1) directs attention to the risk which has materialised. 140The relevant risk for consideration is the risk of harm, the materialisation of which gave rise to the decision, s.5L aside, that the defendant was negligent in the first place. Here, as I have said at [108] above, that risk is the risk of the plaintiff suffering appreciable, rather than transient, physical injury from falling and colliding with the riverbed. However, I bear in mind s.5F(4) set out above which seems particularly apposite in a case concerned with river-based activities. 141I reiterate my acceptance, for the purpose of this contingent finding, that there is no necessary correlation between the significant risks which make an activity dangerous, and the obvious risk that materialises, notwithstanding Basten JA's compelling analysis to the contrary. However, on the basis that the activity undertaken was wakeskating in the channel, the considerations set out at [135] above lead me to conclude that the risk as formulated would not have been obvious to a reasonable person in the position of the plaintiff. Indeed on the basis that the activity was to be carried on wholly within the channel, a reasonable person in the position of the plaintiff (or of the defendant for that matter) would have been justified in putting the risk to one side as insignificant or trivial. I have not overlooked that a slight risk, one having a low probability of occurring, might yet be "not insignificant", and even "significant", when the resulting harm if it materialises is likely to be serious. 142For these reasons the defendant's s.5L defence fails. Although pleaded, neither contributory negligence, nor s.5I, nor volenti non fit injuria were pressed. Orders 143My orders are: (1)Judgment for the plaintiff on the question of liability with damages to be assessed; (2)The defendant to pay the plaintiff's costs of the determination of the separate question of liability forthwith after they have been agreed or assessed; (3)List the matter for directions before the Common Law Case Management Registrar at 9:00 a.m. on Friday 27th September 2013. ********** DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. The onus remains on any person using material in the judgment or decision to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court or Tribunal in which it was generated. Decision last updated: 30 August 2013