Abstract: A water ski brake apparatus includes a water ski having a tip, a tail, and a top and bottom, and having a vane attached to the bottom of the water ski. The water ski has a ski boot having a toe and heel with the front of the heel being hingedly attached to the top of the water ski. A drag inducing foil is movably attached to the vane in a predetermined position thereon and is shiftable between first and second angular positions. A linkage is attached to the boot heel at one end and to the drag inducing foil at the other end and is shiftable between a first and second position responsible to movement of the boot heel on the boot hinged to shift the drag inducing foil between first and second positions to thereby brake the water ski by increasing the drag when the drag inducing foil is shifted to a second position in the water at the control of the skier by varying his weight distribution in the heel portion of the boot.

Abstract: A wind propelled sailing apparatus having a sailboard hull adapted to support a user; a sail for propulsion of the sailboard hull and adapted to receive wind for motive power; a skeg positioned and oriented in a rear central portion of the sailboard hull, the skeg being adjustable between a first position, whereby the skeg has a surface area sufficient to provide lateral resistance to side forces generated by the sail and to provide directional stability to the sailboard hull when sailing upwind, and a second position, whereby the area of the skeg is reduced for sailing downward; and a housing for the skeg which facilitates vertical upward and downward movement thereof, the housing having an opening configured and positioned about the skeg to minimize air entrainment between the housing opening and skeg to the underside of the sailboard hull due to forward movement thereof.

Abstract: The invention relates to fins for watercraft such as surfboards, surf-skis, sailboards, kayaks, canoes, skiffs, water-skis, and also "soft" plastic watercraft such as polyethylene boards. These fins have an apertured, basal flange; each fin being affixable, in a variety of positions, to the underside of the watercraft via fixing means extending through the apertures in the flange and into the fabric of the watercraft.

Abstract: A lift producing device is disclosed which is adapted to be connected to a vehicle to provide lift to the vehicle when the vehicle is moved relative to a first fluid medium having a first density and viscosity and being in contact with a second fluid medium adjacent the vehicle. The second fluid medium has a second fluid density which is different from the first fluid density. The lift producing device comprises opposed first and second major surfaces joined at a longitudinally extending leading edge and at a longitudinally extending trailing edge, with at least a portion of the longitudinally extending leading edge being spaced from the longitudinally extending trailing edge by a predetermined mean chord length.

Abstract: An aquatic "dive-plane" which operates in tow behind a motorcraft. Used in conjunction with basic snorkle gear it permits the user, by the flexing up or down of peripheral wings to submerge and explore under the surface as well as to turn, maneuver and resurface intermittently for air. It comprises a body of buoyant material to float the unit for easy recovery; a pair of semi-parabolic structures of a rigid, durable transparent material which serve hydrodynamically to minimize drag and to protect the face and mask from turbulence while allowing the user a maximum view of surroundings both above and below the surface; a pair of peripheral wings manually controlled by affixed handles by which the user controls his position in the water; a pair of arm-supports by which the user stabilizes his position in relation to the dive-plane and by which an even distribution or shifting of the pulling tension is permitted.

Abstract: A replaceable skeg for a marine propulsion device is provided and includes a tapered dovetail tongue and groove joint between top of the skeg and lower portion of a gear case housing on the marine propulsion device. When the skeg is hit by an underwater obstruction it will fracture at the joint and break away, leaving the lower portion of the gear case housing intact and undamaged in which another skeg can be installed thereto.

Abstract: A keel assembly for a water craft. The keel assembly has a body having an aerodynamic cross section with a pair of side faces and a leading edge section. A portion of the leading edge section is movable relative to the body. A pair of vanes are spaced from and connected to the leading edge section to be disposed within a flow of water past the body. A pair of arms join the vanes with the portion. Movements of the vanes pivot the portion toward the direction of flow of the water to offset the effects of a negative pressure region occurring at the leading edge section.

Abstract: The present invention provides a surfboard which includes, in the lower aft region, a vertically narrow flexible tongue, the bending range of which is restricted by an elastic device, and, in the upper aft region, a covering material. Two supports are arranged one behind the other in the surfboard's longitudinal direction. A rear support is secured to the tongue, and a forward support is located in the region of the forward end of the tongue or in front of the tongue. A stringer is provided for elastically connecting the front and rear supports. The surfboard provides a simple and space-saving design.

Abstract: An aquatic board construction for sail boards, surf boards and the like has shaped upper and lower sections which are joined together with a generally hollow interior. Each section has a sandwich construction with high strength outer and inner skins, and a core formed from a filler material sandwiched between the two skins. The skins are preferably formed from multiple layers of a thermosetting resin impregnated into a fabric material. The outer skins extend beyond the sandwich construction of each section, with the two sections joined together along the extended portions of their outer skins. Receivers for accessories such as a fin, mast and the like are formed integrally with the board structure. The receivers have transverse flanges which are lodged between the inner and outer skins to retain the receivers in place. Structural webs having a similar sandwich construction to the board sections may be provided through the hollow interior of the board. The completed board is high strength yet light weight.

Abstract: An attachment of a fin to an adjustable fin holder of a surfboard or sailboard that protects the fin, fin holder and board structure around the fin holder from damage if the fin strikes an underwater object. The attachment includes a flexible slide member which deforms, permitting release of the flexible member from grooves in a slot in the bottom of the board.

Abstract: The rear of the float (1) is cut away in order to provide said float with a lower rear portion or "lift" (4) which exhibits a certain compliance relative to the float. The rear portion or "lift" (4) is overlapped at a certain distance by a rigid body (3) which is integral with the float (1). A slot (5) is thus defined, with which a double-acting damper (6) is associated. Depending on the state of the water surface, the portion (4) assumes one of the positions C, C', C".

Abstract: A surfboard is provided with fins, at least one of which is canted at an angle to the longitudinal axis and also tilted relative to the surface of the board, and reinforcing fibers are applied to extend continuously from along the fin to along the board, and adhered to each.

Abstract: The combination of a body surfboard (10) and a pair of floats (20) and (21) attached together by fasteners (30), (31) and (32) passing through holes (35), (42) and (44) in the float members and similar holes in the board. A reinforcing web (50) bonded to the outer surface of a portion of each float and a reinforcing rod (52) inserted into a hole drilled from the end of each float serve to reinforce each float against breakage while allowing limited bending of the rear extension (27).

Abstract: A surfing toy is provided in the form of a surfer standing on a surfboard, the two desirably being molded integrally. The device actually surfs, i.e. it stays at the front of a wave even if the wave foams, and rights itself quickly if it is knocked over by a wave. Important features include the provision of a weighted keel which is located below the rear half of the board. The board is desirably much wider than a conventional surfboard relative to its length.

Abstract: A retainer is described for holding the fin box of a surfboard, windsurfer, or small sailboat very securely to the rest of the board to greatly resist breakout of the fin box from the board, which is of relatively low cost and of light weight. The retainer is formed primarily of foam of a density greater than the foam in the rest of the board, and is molded to the fin fox to bond thereto. The retainer extends up from the fin box so the assembly formed by the retainer and fin box has a height equal to the thickness of the unfinished board. A groove is cut in the unfinished board through the entire thickness of the board, and the retainer/fin box assembly is placed in the groove with the upper and lower surfaces of the assembly even with the upper and lower surfaces of the unfinished board.

Abstract: A water craft is of one-piece construction having a bow section provided on the underside with a pair of parallel runners and a recessed central portion. In addition, the craft has a stern section which narrows toward the rear and which has a chine on the underside in spaced relation to the runners to provide two channels for a flow of water. A stern section also has a flat deck for seating or standing of a user thereon depending upon the use of the craft, for example, as a rescue craft or as a sail boat.

Abstract: A kneeboard is provided with a pair of retractable fins which are operated by a control knob mounted on the board in front of the user's knees. The control knob is connected to the fins by a pair of cables. The fins can be raised or lowered simultaneously by sliding the control knob forwardly or rearwardly.

Abstract: Board with rudder comprising on its lower face at least one rudder mounted for swivelling in the body of the board and actuatable by a means accessible on the upper face of the board, disposed substantially in the central zone of the board and formed of two manual members separated by a profiled portion formed so as to allow the user to lie on the board with his chest along said profiled portion, said board being provided in its rear half-portion, on its upper face, with two parallel elongate housings formed in the mass of the board for receiving the leg portions of the user below his knees, when kneeling on the board.

Abstract: A towable surfboard including a hull formed in its fore portion with a bow having on its underside a modified deep-vee configuration and extending rearwardly to form on its underside of its aft section a flatter bottom configuration. A seat is mounted about 3/4 of the way back on the deck and heel cups are mounted forwardly thereof such that a rider may sit on the seat with his heels received in such cups and grasp a tow rope to be towed behind a power boat.

Abstract: A planing-type hull has a keel which projects downwardly from a disk which is mounted in the bottom of the hull for limited rotational movement about a vertical axis located rearwardly of the center of the keel. In a second embodiment the keel projects downwardly from a sector or generally pie-shaped member, which is pivotal in the bottom of the hull between two limit positions. A spring-loaded detent may be employed to return the keel to a centered position.

Abstract: A fin for a sailboard has a pair of high aspect ratio foils disposed in tandem in which the trailing edge of the forward foil is spaced apart from the leading edge of the aft foil. The fin permits high speed and rapid maneuvering without ventilation and stalling by reducing spanwise flow of water and loss of laminar flow at high angles of attack.

Abstract: A method of attaching a fin to an adjustable fin holder of a surfboard or sailboard that protects the fin, fin holder and board structure around the fin holder from damage if the fin strikes an under water object.

Abstract: A structure for mounting fins to the under side of a surfboard includes an elongated molded fin socket member which defines an interior rectangular slot configured to receive a rectangular base of a fin member. The fin socket further defines an upwardly extending cover recess coextensive with the slot. The fin socket is adhesively secured within a contoured recess within the surfboard foam core prior to the laminating operation. After the surfboard has been laminated with the fin socket in place such that the laminating materials overlap the fin socket, the upwardly extending portion of the fin socket is removed and ground flush to the laminated surface of the surfboard to expose the rectangular slot. Thereafter, the fin is adhesively secured within the slot.

Abstract: A rescue fin is a device for repairing a broken skeg box on a sailboard without the need to take the sailboard to a repair shop. The rescue fin is strapped to the rear part of the sailboard so that the skeg box of the rescue fin is positioned above the broken skeg box and is strapped in place using straps positioned on both sides of the skeg board. the device can be carried on the sailboard or by the operator of the sailboard and can be installed on shore or in the water.

Abstract: A rudder-steerable water ski is provided including a pivotable shoe rotatable by the user to correspondingly move a ski rudder through a transmission mechanism. A V-shaped rudder may be used with at least one blade of the rudder remaining in the water when the ski is angled with respect to the surface of the water. According to the method of the present invention, the conventional water ski may be modified to provide the rudder-steerable capability of the invention.

Abstract: A laterally unstable small water craft such as a sailboard, a kayak, a canoe, a sailfish, a sunfish, or the like is provided with laterally extending narrow stabilizing wings of relatively shallow vertical dimension that limit tilting of the craft. Preferably the wings are provided with mounts that permit independent adjustment of the wing rake angle, dihedral angle and angle of attack, and the wings may be folded to positions entirely between the longitudinal sides of the craft. Conveniently the wings and their mounts are provided as a kit for attachment to any particular type of small water craft.

Abstract: A novel fin for surfboards and watercraft that includes a pivoting rudder-like section that swings out when a turn is commenced, enhancing the maneuvrability of the surfboard by reducing the resistance of the fin as it moves sidewards through the water in a turn and by redirecting the water flow through the pivoting rudder section in the direction of the turn. A fixed blade attaches to the surfboard and a separate pivoting fin section is joined to the fixed blade by two pivot pins. Protruding from a vertical hole in the top of the pivoting fin section is a spring loaded pin which presses into a channel in the underside of a foil integrated into the underside of the fixed blade mounting section. The channel is deepest in the center of the foil thus the spring loaded pin in travelling back and forth along the channel seeks the deepest portion which tends to align the two fin blade sections.

Abstract: An improvement to a wave ski comprising an adjustable seat which slides longitudinally along a track located on the upper surface of the wave ski and a fin associated with the seat, whereby the user can simultaneously adjust the longitudinal position of the seat by the use of footrests and the fin on the wave ski. In another embodiment of the invention, the adjustable seat which moves longitudinally along a track located on the upper surface of the wave ski and the fin associated with the seat includes a slot extending longitudinally along or adjacent to the center line of the wave ski and is adapted to receive the fin or portion of the seat, whereby the user can again simultaneously adjust the longitudinal position of the seat and fin on the wave ski.

Abstract: A water ski or similar equipment comprising a platform 10 having a downwardly projecting fin, the fin 11 or the platform 10 having means for deflecting the water laterally of the direction of travel through the water, such means being, in one example, a pair of wedge shaped components 12, 13 secured at opposite sides of the fin 11 to present respective angled external surfaces.

Abstract: A steerable surfing body board for use by a surfer to a hydroplane down the front face of a wave. Two rudders are mounted near the front of the board and two skags are mounted at the rear. A control handle on the upper surface operates the rudders in parallel through a cogged belt between the rudder axles in the center of the board. The handle is offset 45.degree. from the position of the rudders placing the straight ahead position of the rudders in the center of the natural arc of the hand when the elbow rests on the upper surface of the board.

Abstract: A breakaway surfboard fin holder is provided which is used in conjunction with a surfboard having a fin supporting channel mounted in the lower, rear surface of the surfboard. A fin is provided having an anchoring tongue extending rearwardly along the top of the fin. A support pin is carried by the anchoring tongue and slidably engages elongated grooves formed in the channel. A breakaway tab is carried by the forward portion of the fin so that, when the fin strikes an obstruction, the breakaway tab fails at a predetermined level of force so that the fin itself is not damaged, but may be reused by insertion of a replacement tab and remounting of the forward portion of the fin in the fin supporting channel.

Abstract: A device for converting and stabilizing a narrow backed water ski member for use by beginners or handicapped persons which includes a stabilizing and training member attachable to the narrow aft portion of a narrow backed ski, the training member including an integrally elongated U-shaped member having side legs of the U-shape fitted alongside the aft ski end portion, and an aft extension on the U-shaped member interconnecting the aft ends of the side legs and fitted against the aft edge of the ski member, and securing elements for removably attaching the training member to the ski aft portion. The training member selectively increases the width and length of the aft end of the ski for increasing the area in contact with the water to enable the narrow backed ski member to be utilized as a broad backed ski member for training purposes.

Abstract: A sailboard including a centerboard contained in a housing and which may be pivoted by the foot of the user from the upper face of the sail-board. In order to provide a simple and inexpensive actuation device for the center-board and which practically prevents any possibility of injury, the center-board is provided with a pawl which may be inserted into one of the ratchet recesses provided on or in the housing of the centerboard. The pawl is carried by a slide which may be radially displaced in the centerboard with respect to the axis thereof. The outer end of the slide is provided with an actuation member and a spring holds its ratchet position. When the center-board occupies a middle position, the slide is approximately perpendicular to the surface of the sailboard.

Abstract: The present invention entails a combination surfboard-kneeboard. The multi-purpose aquatic board of the present invention is provided with detachable fins, ankle strap, and knee strap in order that the same can be utilized for either surfing or kneeboarding. Further, the board is elongated and includes a lower base portion and a raised upper deck having a cavity formed therein. A resilient pad, such as a neoprene pad, is secured within said cavity to form a resilient upper deck about a substantial portion of the board.

Abstract: A water ski of conventional form so far as general contour and leading end uptilt is concerned, has two tunnels or grooves formed in its underface and a fin in each tunnel which projects downwardly from the trailing end portion of its tunnel. The tunnels:1. are arcuate in cross-section,2. begin in a point short of the leading edge of said underface and end at the trailing end of said underface, and3. at said point are of zero width and depth and, proceeding to said trailing end, progressively increase in both of these lateral directions.

Abstract: A hand-toboggan to accommodate a seated or kneeling rider and having a bottom surface with a longitudinally extending medial portion and two opposite flanks upwardly and outwardly inclined from the medial portion, a pair of parallel longitudinally extending ribs bordering the medial portion, and a plurality of parallel inwardly curving ribs on each of said flanks to enable the rider to turn the toboggan in whichever direction he should lean.

Abstract: A board for aquatic sports is disclosed. The board, during displacement across water, directs a jet or shower of water at the abdominal region of a person lying on the board.

Abstract: A fin which can be secured in the channel of a curved fin box in a plurality of locations. The fin has a grooved flange which mates with the open channel of the fin box. One wall of the channel has a groove which aligns with the flange groove and a fastening rod is inserted therein. The fin is prevented from longitudinal movement within the channel by a tab and tab receiving. A pair of the curved fin boxes and fin are affixed to a surfboard as thruster fins. The manuverability of the surfboard is enhanced and can be varied by the repositioning of the thruster fins within the curved fin boxes. At one extreme the line of the fins is parallel to the center line of the surfboard, and at the other extreme the thruster fins are toed-in and form equally but oppositely directed angles with respect to the center line.

Abstract: A water ski fin is carried by a housing mounted to the upper surface of the rear end of a ski with the fin extending downwardly through an elongated slot in the ski. The fin carries a transversely extending wing thereon and the combination is capable of being pivoted relative to the housing and ski to thereby change the angle of the wing. Movement is accomplished by a handle on one side of the housing which rotates a cam element which, in turn, engages an opening in the fin adjacent the top thereof. A locking device maintains the wing and fin in the desired position by preventing further movement of the cam element.

Abstract: A fin system for surfboards, wind surfers or similar sporting equipment having an elongated channel extending lengthwise underneath the board. The fin is adjustable in the channel by the interaction of a resilient finger cut out of the fin base with a ribbed inner surface of the channel. The fin is totally removable from the channel, and when inserted, moves along the channel by pressure applied to the base of the fin. Releasing the pressure on the base causes the resilient finger to engage a notch in the ribbed surface and securely positions the fin at the desired point in the channel.

Abstract: A board for sliding on snow is provided and has nose, intermediate and tail portions. The nose and tail portions have a thickness that will not deform under the weight of a user. The intermediate portion has a thickness that it will elastically bend under the weight of a user. The board is shaped into an inverted arch and has a side plate mounted on each of the side edges to extend longitudinally thereof. Step-decks for the user's stance are located on the respective connections between the nose and intermediate portions and between the intermediate and tail portions with the step-decks being inclined downwardly toward the intermediate portion. The tail portion has at least one pin tail configuration and includes a fin-box embedded at the bottom of said pin tail. The fin-box includes a fin which is detachably mounted therewithin such that the fin will be released when a force is applied thereto that is stronger than a predetermined level.

Abstract: The device comprises a casing adapted to be secured, as by gluing, to the sailboard, the casing having a downwardly opening, mortise-defining recess surrounded at its lowermost end by a peripheral flange, the centerboard having a tenon at its upper end adapted to be received in the mortise, the centerboard having a shoulder at its front end adapted to engage the peripheral flange, the tenon terminating rearwardly in an outwardly opening bore having resilient lips adapted to be snap-fitted around a hinge pin extending horizontally between the opposite sides of the mortise, the mortise including a self-locking attachment adjacent its front end releasably engagable with the front end of the tenon to secure the centerboard in the mortise in its normal position of use, the centerboard being readily inserted in and removed from the mortise and pivotable about the hinge pin if it strikes an obstruction.

Abstract: An apparatus for securing a fin to the bottom surface of a surfboard and comprising a uniquely configured fin box designed to provide a more secure structural relationship between the fin box and the surfboard. The invention is also designed to provide a more secure means for securing the fin within the fin box to prevent inadvertent loss of the fin while still providing a more advantageous means for releasing the fin from the fin box when removal of the fin is desirable. More specifically, the present invention comprises a fin box of substantially rectangular configuration and designed to be embedded within the underlying surface of the surfboard whereby the exterior surface of the fin box lies flush with the exterior underlying surface of the surfboard. A novel flange integral with the fin box is included to provide added structural resistance to transverse forces that normally occur during surfing which would otherwise tend to cause rotation and loosening of the fin box within the surfboard.

Abstract: One or more vanes of a rigid or flexible material are attached to the underside of a liferaft or other towable marine craft. The vane or vanes are suspended from the craft at an angle of 90.degree. or less relative to the direction of towing.

Abstract: A highly maneuverable water sled device is disclosed which includes a joystick for controlling a rudder and an elevator. The base of the water sled device is provided with upwardly extending, hollow side, front and rear walls which are individually fillable with water to vary the buoyancy of the device. A preferred embodiment of this invention further includes a hydrofoil assembly downwardly extending from a forward section of the device and a flotation mattress attached to an upper surface of the device to provide for user comfort and to further allow the buoyancy of the device to be controlled.

Abstract: A surfboard fin is disclosed which is formed of shaped plastic opposed members which are joined and sealed to form a hollow light-weight buoyant construction, which provides an external contour to reduce drag in surfboarding. The novel profiled plastic surfboard fin is readily mounted to conventional boards and replaces the present conventional fiberglass fins.

Abstract: A surfboard with a fin is developed to counteract the tendency for skegs or fins to "pop out" especially when the surfer "walks the nose" of the surfboard or rides high on a wave. The fin has a pair of opposed wing hydrofoils extending laterally from an approximately mid-point position on a vertical hydrofoil having a forwardly arcuate relieved portion above the wing hydrofoils, a downwardly-rearwardly swept leading edge and a rearwardly-upwardly swept trailing edge terminating at the confluence of the rear edges of the wing hydrofoils.