AU2008330290A1 - Improvements in and relating to wave pool construction - Google Patents

Description

WO 2009/070036 PCT/NZ2008/000313 IMPROVEMENTS IN AND RELATING TO WAVE POOL CONSTRUCTION Technical Field 5 This invention relates to improvements in and relating to wave pool construction. In particular, this invention is directed to provide an improved continuous wave pool apparatus, method of construction and methods of operation. The present invention relates to a wave pool particularly designed for surf-riding 10 It is envisaged the invention will be applicable for use in recreational and competitive wave and surfing pool facilities. However, the invention may have applications outside this field. For example, the invention may be used to provide training facilities for surfers, for testing surf board design and so forth. 15 Background Art A continuous surfing pool consists of a channel with wave generators. The waves move endlessly around the channel and return to 'their starting position multiple times. 20 This is contrary to a typical surfing pool where the waves are generated at one end of a broad channel, they break in the pool on a reef and then the wave is damped or dissipates by breaking at the other end of the pool (US Patent No. 6,912,738). The problem with these pools is that the surfing ride is limited in length, unlike the continuous channel where the 25 surfing ride can continue for as long as the surfer wishes. In another type of invention, water flow is used to create a standing wave which forms on a steep incline in the channel (US Patent Nos. 6629803, 6932541, 6019547). The problem with these devices is that the waves are not propagating around the channel, instead they form on 30 the sculpted step and remain in place, similar to standing waves in a river. As such, the principal means of forming the wave is through current flow and so the device does not 1 WO 2009/070036 PCT/NZ2008/000313 provide a surfing ride similar to the ocean, where the wave moves laterally and the surfer rides on the wave face as the wave moves shoreward Other inventions have revealed a means to generate waves which can be used in pools (US 5 Patent No. 6336771), but they do not disclose the means to take this generated wave around a continuous channel smoothly without losing a substantial fraction of the energy of the wave as it moves. In US Patent No. 6928670 a method to generate a wave using a moving generator has been revealed. While the surfer is moving, the wave is not constrained to a channel and the best surfing ride occurs near the generator itself. 10 One invention reveals a continuous wave pool (US Patent No. 3,913,322). In that device a wave generator runs around a ring which is internal to a circular pool. The wave generator is like a plow moving through the water which puts out bow waves that are said to be suitable for surfing. 15 In US Patent No. 6,920,651 B2, the inventor reveals a circular pool with continuous waves that break around an inner island. Around the outer perimeter of the circular channel are large number of wave generators that point directly to the centre of the island and are synchronized in their action to produce waves that travel around the circular ring-shaped pool in an endless 20 loop, therefore creating an endless surfing wave that never ends. The problem with this device is that the waves break and reflect off the inner ring and so they cannot travel smoothly around corners without the use of generators on the corners. In addition, the device requires a large number of wave generators that must be placed in deep water around the outer ring. Such a device will also experience strong currents in the direction of the waves which arise 25 when the wave break due to a force known as radiation stress. No measure to overcome these problems has been described by the inventor. In another embodiment of the continuous surfing ride (US Patent No. 5,387,159), the inventor describes a horizontally-positioned rotatable cylindrical housing cradled in a frame structure. 30 The problem with this invention is that the wave is not traveling along a channel like a surfing wave on a beach or in a channel with naturally moving waves. 2 WO 2009/070036 PCT/NZ2008/000313 Several wave generators have been described. The closest to an endless wave is the plough shaped moving generator described by US Patent Nos. 4,792,260 and subsequently by US Patent No. 6,928,670. Such a generator can be towed through the water around a lake to create an endless wave generation, but the waves spread outwardly from the plough as it 5 passes through the water like the wave of a vessel. This does not provide an endless continuous surfing ride, unless the surfer remains very close and on the immediate face of the plough. The device is not useful for making endless waves in a channel. The problem with the previous inventions is that 10 - No solution has been provided to enable waves to move around a continuous channel, particularly around corners without using wave generators on the corner e Another problem is that the wave decays, breaks or collapses on the inner wall of the channel 15 e A third problem is that the breaking waves will create unwanted currents around the ring * A fourth problem relates to finding the means to re-use the residual wave crest that returns to the starting point and thereby reduce the cost of wave generation e A fifth problem relates to finding the means to place the wave generators in a side 20 channel which links with the continuous pool. * A sixth problem is that an improved means to make the wave break has not been described. While the present invention has a number of potentially realisable applications, it is in relation 25 to addressing problems associated with existing systems that the present invention was developed. It was also developed with maximizing the enjoyment of the surfer utilizing the pool. It would be useful therefore, to have a wave pool construction that: 30 1. Provided a continuous surfing pool in which the waves move endlessly around the channel and return to their starting position multiple times 3 WO 2009/070036 PCT/NZ2008/000313 2. Enabled waves to move around a continuous channel, particularly around corners without using wave generators on the corner 3. Minimised or obviated wave decays, breaks or collapses on the inner wall of the channel; and 5 4. Minimised the creation of unwanted currents around the ring; and 5. Was effective at re-using the residual wave crest that returns to the starting point and thereby reduced the cost of wave generation; and 6. Placed the wave generators in a side channel which links with the continuous pool thereby avoiding the need to have wave generators in the surfing pool area; and 10 7. Offered an improved means to make the wave break; and 8. Contributed to an improved in-pool surfing experience; and 9. Provided an alternative to present systems employed;, and 10. Provided a consistent wave product, so that reliability of performance of the wave pool could be achieved.; and 15 11. Would be easy to use. It would therefore be advantageous to have an invention that offered at least some, if not all, of the potential advantages of the above proposed wave pool system. It is therefore an object of the present invention to consider the above problems and provide at least one solution 20 which addresses a plurality of these problems. It is another object of the present invention to at least provide the public with a useful choice or alternative system. Further aspects and advantages of the present invention will become apparent from the 25 ensuing description which is given by way of example only. It should be appreciated that variations to the described embodiments are possible and would fall within the scope of the present invention. 4 WO 2009/070036 PCT/NZ2008/000313 Disclosure of Invention Wave pools are man-made channels of water in which waves are created to mimic waves in an ocean. A wave pool is typically operated in conjunction with a wave generating machine 5 located at a designated point around an edge of the pool. The wave generating machine creates periodic waves that travel along the pool channel. The present invention is directed to the apparatus and methods of manufacture and operation of an improved continuous wave pool. . For good surf-riding, the waves should be high in 10 height and long in period but also steep enough to break at their top along the crest line. A problem with many existing wave pools is that the wave has a shortened wave period as the wave decays and thus the surf ride may be limited. In addition, limitations in the length of wave pools may mean the height of generated waves is kept low and so may not appeal to some surfers. 15 The present invention is directed to providing a wave pool where the wave is continuous and obviates the need to continually generate completely new waves and yet is not detrimental to wave formation or maintenance. The ride is in effect extended without the need to physically extend the pool size. This invention enables multiple traveling waves to be generated which 20 can be used by multiple surfers at the same time. The ride length is determined then primarily by the surfer's ability to stay with the wave. In addition, the wave formation may be variable across the wave, thereby suiting both inexperienced and experienced surfers who can choose where along the wave the conditions match or test the surfer's abilities. 25 The present invention is also achieved without the need to have multiple wave generators located in or around the interior of the pool wall. According to one aspect of the present invention, there is provided a continuous wave pool for surfing including a continuous channel with side walls and a sloping bottom of near 30 parabolic shape on the corners with the shallowest depth on the inside of the corner and deepest depth on the outside of the corner, said sloping channel bottom enabling a wave generated in the pool to travel smoothly by refraction around corners of any radius or shape. 5 WO 2009/070036 PCT/NZ2008/000313 The near-parabolic slope is designed according to a mathematical formula that allows the wave to be maintained 5 According to another aspect of the present invention there is provided a continuous wave pool substantially as described above wherein the waves are generated via a wave generation system contained in one or more side channels that feed into the main channel. According to another aspect of the present invention there is provided a continuous wave pool 10 substantially as described above wherein the wave generation is timed such that after traveling down the side channel the wave joins smoothly onto a passing residual wave that has already traveled around the continuous channel. According to another aspect of the present invention there is provided a continuous wave pool 15 substantially as described above wherein, the continuous channel includes converging side walls as it approaches the wave generator system to ensure a smooth join of a residual wave with a newly generated wave According to another aspect of the present invention there is provided a continuous wave pool 20 substantially as described above wherein, the side walls will converge and then diverge again in chosen locations around the channel to cause the wave to break. According to another aspect of the present invention there is provided a continuous wave pool substantially as described above wherein, the continuous channel includes a water pumping 25 system oriented such that the flow of the pump is opposite to the currents that are generated in the continuous pool when the waves break. In one preferred embodiment of the present invention, the continuous wave channel is of substantially racecourse shape. Other shapes can, however, be adopted with multiple corners 30 of chosen radius and channel width. 6 WO 2009/070036 PCT/NZ2008/000313 The bed of the channel will be nominally horizontal in the straight sections of the pool, although mild slopes across the channel can be adopted. The parabolic curve is needed to promote travel of the wave around the corners of the wave 5 pool. Accordingly, changes to the floor shape are limited, but can occur depending on the wave pool performance required. However, the intensity and number of the corners can be varied to match the abilities of beginner versus better surfers. Also, the wave pool channel width may be greater for experienced surfers who would use more wave face by riding in a zig-zag fashion. 10 In addition, the wave may be directed into a corner to cause a reflection. This has the effect of creating a wave that surges between the walls and can be used to make the wave break. This would be achieved to a greater degree as the floor shape becomes less closely aligned with the parabola. Thus, other wave effects can be created by reflecting the wave off the wall 15 of the continuous wave pool. To allow the waves to travel smoothly around the corners, the bed of the channel is tilted across the channel according to the following method which adopts wave refraction to turn the wave around corners. 20 Waves in shallow water travel at a speed that is governed by the water depth. To a reasonable approximation, the forward propagation speed V of the wave is given by the formula: V =(gh)1 2 (la) 25 where h is the water depth and g is gravitational acceleration (usually taken as approximately 9.81 ms2). For very steep waves, the speed may be governed by the formula: 30 V = (g(h+H))'2 (lb) where H is the wave height. 7 WO 2009/070036 PCT/NZ2008/000313 By way of example, consider a pool which is circular, although any other winding shape can be adopted. In this example, the corner is continuous around the circle in a pool which consists of two concentric circles with a water filled channel between them. The diameter of 5 the circles would depend on the size of the pool required. If the diameter of the inner and outer circle are Dinnner and Douter.respectively, the circumference of the two circles is given by: Cinner = 7c Dinner (2) Couter= m.Douter 10 where 7c =3.1417 The time of travel for the wave to move one full loop around the outer circle is: 15 Time of Traveluter = Coute,/Vouter = Contter/ (g.holite)= 2 2c Doute,/(g.houter) 2 (3) where Votte,. is the velocity of the wave, houter is the depth of the channel along the outer wall. The time of travel for the wave to move one full loop around the inner circle would be 20 Time of Travelinner = Cinner/Vinner =Cinner /(g. hinned 12 = 7r .Dinne,/ (g.hlnerd 12 (4) And Vinner is the velocity of the wave, hinner is the depth along the inner wall. 25 If the wave is to travel around the corner smoothly, the time of travel around the outer wall should equal the time of travel around the inner wall, i.e. Time of Traveluter = Time of Travelinner (5) 30 Therefore, Doute,/(g.houtedi 112 = Dinne,/ (g. hinner) 1 2 (6) 8 WO 2009/070036 PCT/NZ2008/000313 And so, hinne,/houter=(DinneDouter) 2 (7a) 5 and for a pool with steep waves near breaking, (hinner+H)/(houter+H) = (Dinne,/ Douter) 2 (7b) 10 The formulae provide the means to calculate the depth on the inner and outer edges of the ring. The same formula can be applied to find the depth across the full width of the channel using the appropriate diameter for each location across the channel, so that all of the wave crest travels smoothly around the corner. By examination of equation (7), it becomes evident that the shape of the floor in cross-section across the channel will be parabolic. 15 With this formula, the depths across the channel can be correctly determined for corners of any radius and shape. It should however be noted that while equation (7) embodies the principle of the invention, 20 the speed of the wave depends on both the depth and the wave height (as in equation lb) and so this will need to be considered for large waves in shallow water and some tuning of the formula will be needed for different water depths, wave heights and wave shapes in the pool (equation 7b). 25 The wave will also take some time to react to the changed bottom depths and so this will need to be allowed for in the design of the channel cross-sectional shape. In all cases, however, the shape of the floor in cross-section will be close to parabolic with a shape embodied in the method described above. While these calculations are only valid for a 30 circle, the principle can be generalised to any corner and to any depth across the channel. 9 WO 2009/070036 PCT/NZ2008/000313 Of course, the depth would be set on the inner circle according to the requirements for the pool. In shallow depths, the wave may be very steep or break. In deeper depths, the wave would be less steep. The former case with sharp corners is most suitable for experienced surfers while the latter case with mild corners would be suitable for beginners. 5 The channel could meander with left and right hand corners and the wave would move around the corner with a straight crest across the channel if the principle of the method described is adopted. 10 The above formulae are an approximation for the wave speed, as the wave speed also depends on wave shape and reaction time taken for the wave to react to the changed depth, and so some small modifications of these calculations will be required for different wave types. These would be usually confirmed in a scale model of the pool to be constructed for testing purposes. 15 For the wave generation, each time the wave crest comes past some extra energy should be added by creating a new wave into the pool so that the generation of the new wave occurs in the pool at the precise time that the existing wave passes. This leads to a resonance where the wave height is constantly reinforced after each revolution and no energy is wasted. As such, 20 the wave generation system is very energy efficient. According to another aspect of the present invention there is provided a method of maintaining a wave in a continuous wave pool for surfing including the steps- of: Initiating an original, primary wave; and 25 Generating a secondary wave at a pre-determined time and having predetermined wave energy; and Supplementing the wave energy in said original wave with wave energy from the generated secondary wave at the point the original wave completes a circuit of the wave pool and passes 30 the vicinity of generation of the secondary wave, said method characterized by the energy of the primary wave being reinforced to maintain the primary wave at the same height it was when originally generated. 10 WO 2009/070036 PCT/NZ2008/000313 According to another aspect of the present invention there is provided a method of maintaining a wave in a continuous wave pool for surfing substantially as described above wherein the supplementary generated secondary wave is generated by a wave generator 5 located at pre-determined locations around the perimeter of the continuous wave pool. According to another aspect of the present invention there is provided a method of maintaining a wave in a continuous wave pool for surfing substantially as described above wherein the wave generator is located within wave generating channels in communication 10 with the continuous wave pool and at pre-determined locations around the perimeter of the continuous wave pool. The above method relies on resonance to build the wave energy using, in effect, booster waves. This system obviates the need to generate a completely new wave for the continuous 15 pool for each surfing ride. The surfing ride is maintained using the same wave which is "boosted" to maintain its wave energy with each successive merging of the generated "booster" waves. In addition, there could be more than one wave in the continuous pool channel at any one time 20 and there could be more than one wave generator at multiple locations around the channel, depending on the length of the channel. Accordingly, there may be multiple surfers in the pool, with sufficient waves available to meet each surfer's needs. One additional option for the wave generation is to have one or more side channels, each 25 containing wave generators. The wave is generated in the side channel so that it joins smoothly with the wave passing in the continuous pool. The smooth join is enabled by causing the channel of the continuous wave pool to become narrower before the wave generation channel. The width of the narrower section of channel 30 will be determined by the loss of wave height as the wave travels between wave generators and the height of the generated wave. For best results, the wave height in the channel of the 11 WO 2009/070036 PCT/NZ2008/000313 continuous wave pool should be constricted by the converging side walls so that it has the same height as the wave coming from the side channel. At other locations in the pool, it could become narrower over a section and then widen again 5 in order to make the wave break. The wave would usually not break in the pool, although the invention would still work if it did. If the wave breaks, it will cause a current to flow in the direction of the waves. This can be overcome by discharging pumped water with a direction along the channel which is 10 opposite to the direction of the current. The depth on the inner wall of the continuous wave pool channel is usually set so that the wave is cresting, - that is, close to breaking; and this occurs when the wave height is approximately equal to the water depth. Thus, the depth will vary with the wave height that is 15 required in the pool. Typical sizes of the channel may be 2-20 metres wide, although wider channels are possible. The length of the channel may be from 30-500 metres long. 20 It will be appreciated that the invention broadly consists in the parts, elements and features described in this specification, and is deemed to include any equivalents known in the art which, if substituted for the prescribed integers, would not materially alter the substance of the invention. 25 Variations to the invention may be desirable depending on the applications with which it is to be used. Regard would of course be had to effecting the desired wave height, speed and number of waves within the continuous wave pool at any one time. The present invention is differentiated from many existing products by virtue of the specific 30 ability to supplement the energy of a primary wave by merging with a secondary wave generated for this purpose; and by enabling a wave pool to operate with continuous waves for prolonged periods. 12 WO 2009/070036 PCT/NZ2008/000313 Whilst some varying embodiments of the present invention have been described above and are to be yet exampled, it should further be appreciated different embodiments, uses, and applications of the present invention also exist. Further embodiments of the present invention will now be given by way of example only, to help better describe and define the present .5 invention. However, describing the specified embodiments should not be seen as limiting the scope of this invention. Brief Description of Drawings Further aspects of the present invention will become apparent from the following description, 10 given by way of example only and with reference to the accompanying drawings in which: Figure 1 is a top plan view of one embodiment of the present invention showing a continuous wave channel of circular racecourse shape with wave generator channel, constriction for wave breaking and pumping system to cancel out the 15 currents generated by the breaking waves; and Figure 2 is a top plan view of a continuous circular wave pool with example depths and side channel for wave generator, illustrating where the pool becomes narrower when approaching the wave generator to hold up the wave height and provide a 20 smooth link with the synchronous wave coming from the generator channel, in accordance with an embodiment of the present invention; and Figure 3 is a top plan view of a continuous wave pool channel with two wave generators in the side channels and exampling a depth pattern in accordance with an 25 embodiment of the present invention; and Figure 4 is a cross-sectional view of a continuous wave pool channel in accordance with an embodiment of the present invention; and 30 Figure 5 is a cross-sectional view of a continuous wave pool channel including a wave generator side channels in accordance with an embodiment of the present invention. 13 WO 2009/070036 PCT/NZ2008/000313 Best Modes for Carrying Out the Invention With reference to the present invention there is provided a continuous wave pool (generally 5 indicated by arrow 1) for surfing. Said continuous wave pool includes a continuous channel (2) with side walls (3a and 3b) and a sloping bottom (4) of near-parabolic shape (4a) on the corners with the shallowest depth on the inside (5) of the corner and deepest depth on the outside (6) of the corner. The wave pool 10 illustrated in Figure 1 is substantially circular, or racecourse shaped. Other shapes can however, be adopted with multiple corners of chosen radius and channel width as shown in Figure 3. Typical sizes of the channel may be 2-20 metres wide, although wider channels are possible. The length of the channel may be from 30-500 metres long. 15 The sloping channel bottom (4) enables a wave generated in the pool to travel smoothly by refraction around corners of any radius or shape. The bottom of the channel will however be nominally horizontal (as shown at 4b) in the straight sections of the pool, although mild slopes across the channel can be adopted. 20 The depth on the inner wall (3a) of the continuous wave pool channel is usually set so that the wave is cresting, that is, close to breaking; and this occurs when the wave height is approximately equal to the water depth. Thus, the depth will vary with the wave height that is required in the pdol. 25 The continuous wave pool system also includes one or more side channels (7) that feed in to the main channel (2). The side channels include wave generators (8). The wave generators (8) generate a secondary wave which travels down the side channel and joins smoothly onto a passing primary residual wave that has already traveled around the 30 continuous channel. 14 WO 2009/070036 PCT/NZ2008/000313 The continuous channel includes converging side walls as shown at (3c). The side walls converge as the main channel approaches the vicinity of communication of the side channel with the main channel. The converging side walls of the main channel ensure a smooth join of the residual wave with a newly generated secondary wave. The width of the narrower 5 section of the main channel is determined by the loss of wave height of the primary wave (as the primary wave travels between wave generators) and the height of the generated wave. For best results, the wave height in the main channel of the continuous wave pool should be constricted by the converging side walls so that it has the same height as the wave coming from the side channel. 10 In some embodiments of the present invention, the side walls will converge and then diverge again (as shown at 3d) in chosen locations around the channel to cause the wave to break. The continuous channel also includes a water pumping system (9) including an inlet (at 9a 15 and an outlet at 9b) oriented such that the flow of the pump (as shown at 10) is opposite to the currents (as shown at 11) that are generated in the continuous pool when the waves break. The depth of the main channel would be set on the inner circle according to the requirements for the pool. In shallow depths, the wave may be very steep or break. In deeper depths, the 20 wave would be less steep. The former case with sharp corners is most suitable for experienced surfers while the latter case with mild corners would be suitable for beginners. The channel could meander with left and right hand comers and the wave would move around the comer with a straight crest across the channel if the principle of the method described is 25 adopted. In addition, there could be more than one wave in the continuous pool channel at any one time and there could be more than one wave generator at multiple locations around the channel, depending on the length of the channel. Accordingly, there may be multiple surfers in the 30 pool, with sufficient waves available to meet each surfer's needs. 15 WO 2009/070036 PCT/NZ2008/000313 When referring to the description of the present invention, it should also be understood that the term "comprise" where used herein is not to be considered to be used in a limiting sense. Accordingly, 'comprise' does not represent nor define an exclusive set of items, but includes the possibility of other components and items being added to the list. 5 This specification is also based on the understanding of the inventor regarding the prior art. The prior art description should not be regarded as being an authoritative disclosure of the true state of the prior art but rather as referring to considerations in and brought to the mind and attention of the inventor when developing this invention. 10 Aspects of the present invention have been described by way of example only and it should be appreciated that modifications, additions and variations to and from the invention and above described embodiments may be made without departing from the scope thereof, as defined in the appended claims. 16

Claims (18)

1. A wave pool operated in conjunction with at least one wave generating means located relative to the wave pool, the wave pool including a continuous pool channel, the pool channel including side walls, multiple corners of preferred 10 radius and channel width and a channel bottom, the wave generating means creating original and unique periodic waves adapted to travel along the pool channel, the channel bottom contoured to maintain the created wave as continuous. 15

2. A wave pool as claimed in Claim 1 wherein the contoured channel bottom is substantially parabolic in shape.

3. A wave pool as claimed in Claim 2 wherein the substantially parabolic contoured channel bottom is designed according to a mathematical formula. 20

4. A wave pool as claimed in Claim 3 wherein the contoured channel bottom is substantially parabolic in shape in the region of corners of the continuous pool channel. 25

5. A wave pool as claimed in Claim 4 wherein the parabolic shape of the contoured channel bottom of the pool channel is configured to effect shallowest depth on the inside of the corners of the continuous pool channel and deepest depth on the outside of the corner of the continuous pool channel. 30

6. A wave pool as claimed in Claim 5 wherein the substantially parabolic channel bottom in the region of the corners of the continuous pool channel is configured to facilitate continuous travel of a wave generated in the pool by refraction around corners of any radius or shape. 17 WO 2009/070036 PCT/NZ2008/000313 5

7. A wave pool as claimed in Claim 6 wherein the continuous pool channel includes at least one side channel connected thereto and in fluid communication with the continuous pool channel.

8. A wave pool as claimed in Claim 7 wherein the at least one side channel includes 10 wave generating means.

9. A wave pool as claimed in Claim 8 wherein the wave generating means is adapted to generate a secondary wave in the at least one side channel and direct said secondary wave into the continuous pool channel. 15

10. A wave pool as claimed in Claim 9 wherein each secondary wave generated in the side channel is timed to travel down the side channel and smoothly join onto a previously generated original wave that has already traveled around the continuous pool channel and is passing the side channel as a residual original 20 wave.

11. A wave pool as claimed in Claim 10 wherein the continuous pool channel includes substantially converging side walls in advance of either or both the location of the side channel and the wave generation means to facilitate a smooth 25 join of a residual wave with a newly generated wave

12. A wave pool as claimed in Claim 11 wherein the side walls of the continuous pool channel are configured to substantially converge and substantially diverge in chosen locations around the continuous pool channel as required to control wave 30 breaking of a wave.

13. A wave pool as claimed in Claim 12 wherein the continuous pool channel includes water pumping means oriented such that the flow of the pumped water is opposite to the currents generated in the continuous pool channel when the waves 35 break. 18 WO 2009/070036 PCT/NZ2008/000313 5

14. A method of maintaining a wave in a continuous wave pool for surfing, said wave pool including a continuous pool channel, the continuous pool channel including side walls, multiple corners of preferred radius and channel width and a channel bottom; said method including the steps of: a) Initiating an original, primary wave via wave generating means; and 10 b) Generating a secondary wave at a pre-determined time and having predetermined wave energy also via wave generating means ; and c) Supplementing the wave energy in said original wave with wave energy from the generated secondary wave at the point the original wave completes a circuit of the wave pool and passes the vicinity of generation 15 of the secondary wave, said method characterised by the energy of the primary wave being reinforced to maintain the primary wave at the same height it was when originally generated.

15. A method of maintaining a wave in a continuous wave pool for surfing as claimed 20 in Claim 14 wherein the generated secondary wave is generated by wave generating means located at pre-determined locations around the perimeter of the continuous wave pool.

16. A method of maintaining a wave in a continuous wave pool for surfing as claimed 25 in Claim 15 wherein the wave generating means is located within wave generating channels in communication with the continuous wave pool and at pre-determined locations around the perimeter of the continuous wave pool channel.

17.. A method of generating a wave in a continuous wave pool for surfing, said wave 30 pool including a continuous pool channel, the continuous pool channel including side walls, multiple corners of preferred radius and channel width and a channel bottom; said wave pool including at least one wave generating means located relative thereto, for generating periodic waves adapted to travel along the pool channel, the channel bottom being contoured to maintain the created wave as 35 continuous, said method including the steps of: 19 WO 2009/070036 PCT/NZ2008/000313 5 a) Initiating an original, primary wave via said wave generating means; and b) Generating a secondary wave at a pre-determined time and having predetermined wave energy also via wave generating means; and c) Supplementing the wave energy in said original wave with wave energy from the generated secondary wave at the point the original wave 10 completes a circuit of the wave pool and passes the vicinity of generation of the secondary wave, said method characterised by the energy of the primary wave being reinforced to maintain the primary wave at the same height it was when originally generated and wherein the wave generated in the pool is of a preferred height, period length 15 and steepness when breaking at the crest line to be adapted for surfing.

18. A method of generating a wave in a continuous wave pool for surfing as claimed in Claim 17 wherein the wave generated in the pool has variable formation across the wave adapted to accommodate either or both a surfer's abilities and multiple 20 surfers at the same time. 20