WO 2007/048172 PCT/AU2006/001550 1 "A watercraft fin system" Cross-Reference to Related Applications The present application claims priority from Australian Provisional Patent Application No 2005905882 filed on 24 October 2005, the contents of which are 5 incorporated herein by reference. Field of the Invention This invention relates, generally, to a fin system and, more particularly, to a fin system component and to a fin system. 10 Background to the Invention To date, as far as the Applicant is aware, watercraft, such as surfboards, have their fins attached by a fin root being received within a socket formed in a body of the watercraft. 15 This complicates construction of the body of the watercraft since the socket defining formations need to be taken into account in the fabrication of the body. In addition, due-to the formation of the sockets in the body, the strength of the body is reduced around those sockets and damage to the watercraft often occurs around these socket defining formations as do fractures. 20 Still further, these socket defining formations restrict the angle at which a fin can project from the body. To angle the fins, it is therefore necessary to angle the socket defining formations correspondingly. This further complicates fabrication of the body of the watercraft. Furthermore, a fibreglass covering is used to cover the body of the watercraft. 25 This fibreglass covering is applied such that it covers each fin in order to secure conventional fins to the watercraft. This significantly complicates construction of the watercraft. In particular, the process of applying fibreglass to the fins adds at least one hour to the time required to manufacture the watercraft. 30 Summary of the Invention According to a first aspect of the invention, there is provided a fin system for a watercraft, the fin system including a fin system component comprising a carrier defining a substantially planar mounting surface for adhesive mounting to an external surface of the watercraft; and a 35 mounting formation associated with the carrier for mounting at least a portion of a fin; and WO 2007/048172 PCT/AU2006/001550 2 a fin carried by the carrier of the component. "Adhesive mounting" is to be understood to include attachment by bonding and the use of resins. The mounting formation may be an elongate formation extending substantially 5 parallel to a longitudinal axis of the watercraft. In an embodiment, the component may include a plurality of receiving formations arranged on the mounting formation for receiving locking elements to lock a fin relative to the mounting formation. The receiving formations may be arranged on the mounting formation for locking the fin at one of a plurality of various positions along the length of the mounting formation. 10 The carrier may be a housing having a shaped, ie. a scalloped, leading edge to minimise hydrodynamic resistance and cavitation. Housings of varying sizes, lengths and shapes may be provided so as to accommodate the required size of fin for the watercraft in question. The shape of the mounting surface may also vary to accommodate the amount of adhesive required to attach the housing to the watercraft. 15 In one embodiment, the mounting formation may be in the form of a shaped channel extending parallel to the longitudinal axis of the watercraft. The fin to be received in the channel may have a correspondingly shaped root portion. More particularly, an inner region of the channel may be wider than an opening of the channel with a fin root of the fin being correspondingly shaped to be held captive in the 20 channel and to inhibit withdrawal of the fin in a direction normal to a longitudinal axis of the channel. In another embodiment, the carrier may be a substantially planar member and the mounting formation may be a flat plate standing proud of the planar member, the plate being dimensioned to be received in a slot in a fin root of the fin. 25 According to a second aspect of the invention, there is provided a fin system component for a watercraft, the component including: a carrier defining a substantially planar mounting surface for adhesive mounting to an external surface of the watercraft; and a mounting formation associated with the carrier for mounting at least a portion 30 of a fin. According to a third aspect of the invention, there is provided a fin for a fin system, the fin including: a fin body; and a fin root from which the fin body extends, the fin root having an enlarged foot 35 component to be received in a correspondingly shaped formation of a carrier of a fin system component as described above.
3 The fin may extend orthogonally from the fin root. Instead, to accommodate a variety of shapes of lower surfaces of watercraft, the fin body may project at a predetermined angle relative to the fin root, the selected angle being governed by the shape of a lower surface of the watercraft. 5 Still further, the fin body may be longer than the carrier in which it is received (when viewed in a longitudinal direction) so that a rear part of the fin body is unsupported relative to the carrier to allow flexing of the rear part of the fin. According to a fourth aspect of the invention, there is provided a fin system for a watercraft, the fin system comprising a fin body and an enlarged foot portion, the foot 10 portion defining a substantially planar mounting surface adapted to mount solely adhesively to an external surface of the watercraft, the fin body and the enlarged foot portion being integrally formed such that the fin body projects at an angle of 900 or less relative to the enlarged foot portion, which has foot portion no holes formed therein. The enlarged foot portion may be formed integrally with the fin body as a one 15 piece unit. The invention extends also to a watercraft including at least one fin system as described above with reference to the first aspect of the invention or the fourth aspect of the invention. 20 Brief Description of the Drawings Embodiments of the invention are now described by way of example with reference to the accompanying diagrammatic drawings in which: Figure I shows a three dimensional view of a watercraft, including a plurality of fin systems, each in accordance with an embodiment of the invention; 25 Figure 2 shows a side view of a fin system in accordance with an embodiment of the invention; Figure 3 shows a plan view of the fin system; Figure 4 shows a bottom view of the fin system; Figure 5 shows an end view of the fin system; 30 Figure 6 shows an end view of a variation of the fin system; Figure 7 shows a side view of a fin system, in accordance with another embodiment of the invention; Figure 8 shows a plan view of the fin system of Figure 7; Figure 9 shows an end view of a variation of the attachment of a fin to the 35 housing of the fin system; WO 2007/048172 PCT/AU2006/001550 4 Figure 13 shows a side view of a fin system, in accordance with still a further embodiment of the invention; Figure 14 shows an end view of the fin system of Figure 13; Figure 15 shows a perspective view of the fin system of Figure 13; 5 Figure 16 shows a bottom view of the fin system of Figure 13; and Figure 17 shows a plan view of the fin system of Figure 13. Detailed Description of Exemplary Embodiments In Figure 1 of the drawings, reference numeral 10 generally designates a water 10 craft, in the form of a surfboard, in accordance with an embodiment of the invention. For ease of reference, the embodiments of the invention will be described with reference to its application to a surfboard. However, those skilled in the art will readily appreciate that the invention is readily applicable to other types of watercrafts such as, for example, paddle skis, water skis, body boards or powered watercraft. 15 The surfboard 10 shows three fin systems 12, each in accordance with an embodiment of the invention. Each fin system 12 comprises a fin system component 14. The fin system component or, simply, the component, 14, which is also in accordance with an embodiment of the invention, comprises a carrier in the form of a housing 16. A fin 18 is removably received in the housing 16. 20 The housing 16 defines a mounting formation in the form of a longitudinally extending, outwardly opening channel 20. The channel 20 receives a fin root 22 of the fin 18 therein. The fin root 22 has a bulbous foot 24 received in a wider part of the channel 26 for holding the fin 18 in position relative to the housing 16 and for inhibiting withdrawal of the fin 18 upwardly out of the housing 16. 25 As illustrated more clearly in Figure 4 of the drawings, the housing 16 includes a substantially planar mounting surface 28. The mounting surface 28 mounts the housing to an external, lower surface of the surfboard 10. Ideally, the mounting surface 28 is adhesively secured to the surface 30 of the surfboard 10 via a high strength adhesive. The footprint, i.e. the surface area, of the mounting surface 28 is governed 30 by the adhesive strength required to retain the fin system 12 on the surfboard 10. The fin system 12 includes a locking arrangement 32 (Figure 6) for locking the fin 18 in position relative to the housing 16. The locking arrangement 32 comprises a plurality of receiving formations, in the form of openings 34 (Figures 2 and 3), defined in the housing 16. As illustrated more clearly in Figures 5 and 6 of the drawings, these 35 openings 34 extend at an angle through the housing 16 opening into the channel 24. Grub screws 36 of the locking arrangement 32 are received in the openings 34. The WO 2007/048172 PCT/AU2006/001550 5 grub screws 32 engage the foot 24 of the fin 18 for retaining the fin 18, releasably, in position in the housing 16. Another embodiment of the locking arrangement 32 is shown in Figure 9 of the drawings. In this embodiment, the fin 18 has a socket 38 defined in its foot 24. The 5 socket 38 is lined by a liner 40. A fastener such as an Allen-head screw 42 is received in the socket 38. A tip 42.1 of the screw 42 bears against a steel plate 44 in the channel 24 of the housing 16. This causes the foot 24 to rise into contact with a tapering wall 46 (Figure 5) of the channel 24 to retain the fin 18 in position relative to the housing 16. 10 Instead of the screw 42, the fastener could be a fastener of the type having a cam-like lever on its head for displacing a shank relative to the head to facilitate locking retention of the fin 18 relative the housing 40. As shown in Figure 2 of the drawings, a rear part 48 of the fin 18 is unsupported by the housing 16. This configuration of fin system 12 is intended to be used by more 15 experienced surfers who require fins 18 which have a rear part that is able to flex. As illustrated in Figure 6 of the drawings, and more particularly, as shown in dotted lines, a fin body 50 of the fin 18 is angled with respect to the fin root 52 so that it is not necessary to angle the channel 24 of the housing 16. With this arrangement, a variety of differently angled fins 18 can be accommodated in the fin system 12 without 20 the need for any special construction of the surfboard 30 itself. Referring now to Figures 7 and 8 of the drawings, a further embodiment of the fin system 12 is shown. With reference to the previous drawings, like reference numerals refer to like parts, unless otherwise specified. In this embodiment, the housing 16 is substantially longer than the length of the 25 fin 18. Thus, as shown in dotted lines in Figure 7 of the drawings, the fins 18 can be positioned at various different places relative to the housing 16 to cater for surfers of different skills. It will be appreciated that, by varying the position of the fin 18 relative to the surfboard 30, the balance of the surfboard can be altered. In both embodiments, the leading end 54 of the housing 16 is scalloped to 30 reduce hydrodynamic resistance and cavitation as the surfboard 10 passes through the water. In Figures 10 to 12 of the drawings, yet a further embodiment of a fin system 12 is illustrated. Once again, with reference to the previous drawings, like reference numerals refer to like parts, unless otherwise specified. 35 In this embodiment of the invention, the carrier of the component 14 of the fin system 12 is a substantially planar member 55 defining the mounting surface 28. The 6 mounting formation is in the form of a plate 56 standing proud of the carrier on a surface of the carrier 14 opposite of the mounting surface 28. For aesthetic purposes the planar member 55 is substantially surfboard shaped. The plate 56 mounts the fin 18 to the surfboard 10 by being received in a slot 58 5 of the fin 18. The plate 56 has a pair of opposed receiving formations, each in the form of a longitudinally extending groove 60, defined in it. Grub screws 62 are received through openings in the fin 18 and engage their associated grooves 60 for retaining the fin 18 in position on the carrier 14. The slot 58 is longer than the plate 56 to facilitate longitudinal adjustment of the 10 position of the fin 18 relative to the surfboard 10. As shown in Figure 11 of the drawings, the plate 56 can project at right angles to the carrier 14. Instead, to provide angled fins, the plate 56 may project at a corresponding angle relative to the upper surface of the carrier 16. In Figures 13 to 17, a further embodiment of a fin system 12 is shown. In this 15 embodiment, the fin 18 has a fin body 64 and an enlarged foot portion 66 integrally formed with the fin body 64 as a one piece unit. The foot portion 66 flares outwardly from the fin body 64 and defines a mounting surface 68 for mounting the fin body 64 to the external, lower surface of the surfboard 30. 20 As shown in solid lines in Figure 14 of the drawings, the fin body 64 projects at right angles to the foot portion 66 or, instead, projects at an angle as shown in dotted lines in Figure 14 of the drawings. It is therefore an advantage of the invention that a fin system is provided which does not require holes to be made in the body of the surfboard 30. This ensures that the 25 structural integrity of the surfboard is maintained. In addition, it is easy to adjust the position of the fins relative to the surfboard using the fin system. Thus, the same surfboard can be used by surfers of differing skills. Still further, by providing fins with fin bodies at predetermined angles to the fin root or foot, angled fins can be mounted on the surfboard and can cater for variations in 30 the shape of lower surface of the surfboard. In addition, the housing 16 of the fin component 14 is simply adhered to the body of the surfboard after moulding of the body of the surfboard and it is not necessary for the housing 16 to be moulded into the body of the surfboard. The contact area of the enlarged foot portion 66 with the surfboard 30 provides the necessary 35 strength to retain the fin 64 on the surfboard. Thus, the housing does not intrude into the body of the surfboard and reduces localised stress points in the surfboard.
WO 2007/048172 PCT/AU2006/001550 7 It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as 5 illustrative and not restrictive.