Abstract: A twin wing sailing yacht having a pair of wing appendages depending from a canoe or hull, the wing appendages including structures which support at their lower ends a fore and aft extending ballast tandemly suspended between them. The wings are rotatable about generally vertical axes under the control of collective and cyclic steering mechanisms.

Abstract: An apparatus is provided for reducing the extent of heel of a nautical vessel by applying a buoyant righting moment on the leeward side of a hull of the vessel. Supports are coupled to and extend laterally beneath the hull and carry hollow bulbs on their extremities. The bulbs on both sides of the vessel are each divided by fore and aft partitions into inboard and outboard chambers. A passage is defined between the inboard chambers and a separate passage is defined between the outboard chambers. A first fluid fills the outboard chambers and the passage therebetween, while a second fluid having a specific gravity different than that of the first fluid fills, the inboard, chambers and the passageway therebetween.

Abstract: A surfboard fin intermediate ha a rigid body element with flexible material (e.g. rubber) covering the leading and trailing edges, with a protective material--such as aluminum foil tape--readily removably secured to the flexible material on a small part of the body element to substantially completely cover the flexible material to protect it during manufacture of a surfboard with the fin attached, such as during sanding. The fin with protective material is placed so that the base engages the bottom of a surfboard, resin impregnated fiberglass rope or roving is applied to the base of the fin and the surfboard bottom spaced from the flexible material, and then resin impregnated fiberglass cloth is applied to the fin and bottom surface of the surfboard. After the resin dries, most of the fiberglass cloth exterior of the fin is cut away with a blade, and then any unwanted portions of the fiberglass cloth associated with the fin are sanded away. Then the protective material is removed from the fin, e.g.

Abstract: A surfboard has one or more (e.g. three) fins extending from its bottom surface. Each fin is a rigid plastic body element (e.g. Shore D hardness of at least about 78) with curved leading and trailing edges, a base, and side walls. The edges intersect in a rounded tip, and the leading edge curves back toward the rear of the surfboard. The leading and trailing edges, but not the sides, of the fin rigid bodies are covered with a soft flexible material (e.g Shore A hardness of about 40-100), such as rubber, urethane, or silicone. The flexible elastomeric material has sufficient thickness, softness, and flexibility to protect a surfer impacted by a leading or trailing edge of the fin, and to act as a rudder (provide anti-cavitation action) to provide some board steerability by the surfer shifting his or her weight.

Abstract: A small ship made of plurality of prefabricated sections, which are made at a factory by a plastic deformation process, such as stamping or rolling, and of a dimension, size and shape such that an overland transportation by road thereof is possible. The sections are transported to a site located at a coastal zone, and connected to each other thereat to thereby build a ship.

Abstract: A flexible airfoil section for a wing or a blade comprising a streamlined shape and an elastic structure whose stiffness distribution along its chord and span is tailored to provide a desirable cambered shape with proportional increases in camber with increases in lift, mounted to a supporting structure such that the airfoil sections are free to pivot about axes near their leading and trailing edges. In operation, the foil derives much of its lift from elastic bending deformation of its flexible shape, thereby achieving a higher lift than a symmetric foil at the same angle of attack while postponing the onset of flow separation and stall and, for operation in water, of ventilation and cavitation.

Abstract: An actuating mechanism is provided for controlling external devices by means of coaxial actuating cables or other suitable linkages. The actuator includes an internal slide element movable to selected detent positions by means of a lever arm which pushes against the slide when raised. The slide is returned to its starting position by depressing the lever arm. Indicator openings are provided in the body of the actuator permitting visual inspection of the position of the slide to indicate the control setting selected. Use of the actuator to control and position retractable fins or skegs on a water board is also disclosed. The actuator is positioned on the upper surface of the water board just forward of and between the rider's knees and coaxial actuating cables link the actuator to retractable fins on the underside of the board. The actuator can be easily manipulated with one hand to retract or extend the fins quickly. The indicator feature indicates the fin setting selected.

Abstract: A sailing boat model adapted for exhibition and for actual sailing on water includes a hull, a keel provided on a bottom portion of a midship of the hull to extend downward from the hull, a rudder provided on a bottom portion of a stern of the hull, a mast provided on the hull to extend upward from the hull, sails connected to the mast, the hull, the keel, the rudder, the mast and the sails having relative dimensions which simulate an actual sailing boat, and a balancing weight comprising an auxiliary keel including a keel body to be detachable attached to and extend downward from the bottom of the hull and a balancing mass provided on a lower end portion of the keel body for up-and-down movement relative to the keel body.

Abstract: A strong, lightweight laminar device which can be used as a fin attachment for surfboards and sail boards, or as a skateboard, sailboard or surfboard, per se. The device comprises a lightweight core and one or more layers of strengthening material surrounding the core. In fabricating the device, a suitably shaped mold is lined with a strengthening layer of carbon fiber. A separating layer of random glass is placed between a first strengthening layer and a second, similar strengthening layer. The space at the interior of the lined mold is filled with an appropriate lightweight, buoyant filler material such as polyurethane foam. After the filler is set or cured, the device is removed from the mold and treated or assembled as desired.

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: 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 invention relates to a profiled device configured as a slotted blade head to improve the efficiency in blade-like structural elements that have a gas or a fluid flowing around them such as foils, vanes of jet engines, propellers, keels of ships or the like. The blade head is formed of a group of profiled blade elements (3) having a laminar profile with radially running slots formed between the blade elements at a distance from the base of blade head. End edges (4) of the blade elements (3) that are consecutive in an initial flow direction (X) are offset relative to each other each in the direction of a pressure zone (6). Slots (2) between the blade edges (4) are of a nozzle-shaped configuration with a flow direction extending from the pressure zone (6) to the underpressure zone (5). The blade elements (3) are located within a profile envelope (73) set by the blade base of the group of blade elements.

Abstract: The craft incorporates a keel (3) essentially constituted by an elongated capacity (4) formed out of a flexible or resilient material which is distortable and watertight. A water inlet opening (6) is provided in the wall of this elongated capacity (4) oriented towards the bow of the craft and maintained in the open condition, in order to have the water back pressure prevailing in this elongated capacity (4) as soon as the craft is moving in the forward direction, said elongated capacity (4) being then at least partially filled with water.

Abstract: Hydrofoil families which have high lift and low drag coefficients. Induced vorticity is partly suppressed by introducing a longitudinal component of the flow directed from the foil tip towards the hydrofoil base at least in the area of the hydrofoil tip. Further increase of the hydrofoil efficiency is attained by reducing the low lift and high drag induced vortex enhancing area along the tip. For given lift requirements the foil area can be reduced and cavitation performance improved. High torsional and bending resistance are attained by using high modulus materials arranged in chosen directions.

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: 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 tandem keel structure (12) for a sailing vessel such as a yacht (10) comprises a main keel (14). A bridge (16) extends forwardly from the foot of the main keel (14) and a forward foil (18) is attached between the forward end of the bridge (16) and the hull of the yacht. The forward foil (18) is separated from the main keel or foil (14) by a slot (20).

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 keel structure connected to the hull of a nautical vessel, such as a sailboat, is provided at least at the junction of the vessel hull and the keel with at least one channel extending substantially lengthwise of the keel for guiding the water displaced by the keel at least partially past a zone, which extends longitudinally of the hull and is aligned with the keel, without lifting it to the surface of water.

Abstract: Disclosed ia a keel for a sailing boat having a hydrofoil section. The thickness to chord ratio of the keel increases from the top to the bottom creating a vortex trap and thus reducing the drag of the keel. A generally horizontal plate at the bottom of the keel is also disclosed and further reduces the drag induced by vortex shedding. In one form the camber of the keel is adjustable. The mechanism for adjusting the camber includes rotatable forward and aft sections faired to a center section of the keel by sheets with a length being a small portion of the total cordal length of the keel. The fairing sheets are fixed along one vertical edge and tensioned by rods located within the rotating forward and aft sections of the keel.

Abstract: A sailboat includes a fixed keel whose lateral profile is adjustable to create lift that counteracts the leeward drift of the boat when sailing upwind. The keel structure supports side panels that are selectively deflected outwardly to form an airfoil. Deflection of the panels is accomplished by the inflation of bladders positioned between the fixed structure and the inner surface of the panels. As the bladders inflate, the forward and aft ends of the panels pivot on hinge supports to the fixed structure, and the length of the panels increases to accommodate the deflection. With the panel on one side of the keel displaced, the keel becomes a lifting body that generates a force acting to force the sailboat in the upwind direction, thereby counteracting the leeward drift caused by the wind acting on the sails.

Abstract: A hard shell shaped to intimately cover the bottom of an inflatable raft. The shell is made of various contoured staves or segments joined together. Straps are used to attach the shell to the raft, bow and transom. A combination transom and mounting frame is used in the raft which do not include a built-in transom. The shell not only protects the raft against abrasion and puncture, but also reduces its drag coefficient, contributes to it stability and enhances its directional control.

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: Arrays of parallel, substantially fore and aft oriented vortex generators are positioned on the keel and rudder of a sailboat to induce vortices at the surfaces of the keel and rudder for the purpose of reenergizing the boundary layers in the water flow past the keel and the rudder to increase the lateral lift in the horizontal plane and to thereby avoid increase in drag associated with keel and rudder stall at high angles of attack with the relative water flow. Similar arrays for the same purpose may be attached to other underwater stabilizing members such as skegs, keel winglets, centerboards, etc.

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 sealing lip assembly for surfboards or sailboats, which closes the underwater side of the opening of the centerboard case or fin case in a virtually flow-tight and non-vortical manner in every position of the centerboard, and including two sealing lips, with each lip defined by a sealing area capable of flexing along the longitudinal axis of the assembly, a resilient area perpendicular to the longitudinal axis, and a mounting portion.

Abstract: Flexible plastic such as polyethylene is reinforced by molding the plastic over a reinforcing member. The reinforcing member is provided with at least one undercut between the plastic and the mold, and the plastic is molded into the undercut so that the plastic and the reinforcing member are interconnected.

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: The present invention describes an inflatable, removable keel for use with an inflatable rubber boat. The keel is interposed between the dunnage and the bottom sheet of the boat and includes at least one tab pair connected to a rigid zone present on the keel. The tab pair bears gripping strips which are adapted to cooperate automatically and removably with complementary gripping strips found on the bottom sheet.

Abstract: An upper and a lower blade are fixed together at an adjustable angle and have means for mounting same on the leading edge of the propeller drive housing of an inboard/outboard motor to cut kelp and other seaweed which would otherwise foul the prop and clog the cool, sea water input vents. The cutter has adjustable brackets which will accommodate a wide variety of different types of propeller drive housings, and will accommodate outboard motors as well as inboard motors, and will even fit on the advance edge a sailboat keel. In one embodiment, it has a combination brace/mesh screen which extends from the cutter to the propeller drive housing in front of the cooling water inlets to keep bits of seaweed and other debris from entering and clogging the cooling system, causing overheating the destruction of the motor.

Abstract: A laterally extending hydrofoil wing is supported in pendulum fashion in a cutout section of a planar keel of a sailing vessel. The pendulum support, in combination with the distribution of mass in the swing wing attempts to maintain the plane of the wing, which is under the surface of a body of water in a position parallel to the surface of a body of water regardless of any rolling or heeling of the vessel. The wing is canted or tilted downwardly into the water in the fore direction of the vessel to plane deeper into the water. When the vessel attempts to roll about its fore and aft axis from its original upright position, the flow of water acting on the canted wing develops a large downward force on the wing and on the keel from which the wing is suspended. The downward force attempts to rotate the keel of the vessel about its fore and aft axis to restore the vessel to its upright position.

Abstract: A keel assembly for a sailboat, the keel assembly having wing-like appendages at the bottom of a fixed keel and having a rotatable flap located at the trailing edge of the fixed keel. The flap includes a cantilevered portion extending below the vertical portion of the keel. In operation, the flap is rotated a few degrees to one side or the other of the center line of the boat so as to create an asymmetrically shaped keel so that the keel and hull exhibit a high lift to drag ratio and efficient sailing performance.

Abstract: A new and improved sailboat hull for traditionally designed, single hull sailboats having a generally tapered lower hull section, whereby the lower hull section is extended rearward beneath the rudder to a point aft of the visible stern. The lower hull extension contains ballast so that the center of gravity of the sailboat is moved toward the stern. The lower hull extension is telescopically adjustable with a direct, corresponding effect on ballast. Horizontal fins extend laterally from either side of the lower hull extension which also has a trim tab attached to its aft end.

Abstract: Detachable single and multiple keels for small boats are taught which are held in place by brackets and straps, the straps being secured to the boat above the waterline.

Abstract: Grounding protective device for sailing vessels and similar boats provided with a fin keel to eliminate to the greatest possible extent the impact effect on a boat when the keel touches ground and to give a long braking distance in order to prevent damage to the boat and the risk of injuries to crew members. A stay is provided in the central plane of the boat which extends from at least either of the end edges of the fin keel at their lower ends to a point so located, that between the point and the fin keel the stay extends at least as deep as any part of the boat.

Abstract: A sailing craft having hydrodynamically shaped catamaran hulls and tapered configuration rudder assemblies attached to each hull. Low draft keels are attached to the fore one-half bottom portions of the hull and a pitch-sensitive variable camber mast and main sail assembly is rotatably mounted on a cross-beam framework which interconnects the two hulls. The mast is constructed and rigged to bow with respect to the longitudinal plane of the sailing craft which passes through the roll axis in response to a high velocity wind force. The bow decreases as the wind velocity decreases and the mast rotates to form a camber adjustment through use of battens attached to the main sail sheet(s). The rudder assembly and control bungy cords and lines permit selective raising and lowering and automatic raising upon contact with underwater obstacles. The deck structure provides for quick dismantling and ease of sailing.

Abstract: A capsize prevention device for a multihull vessel which may be mounted to an existing vessel or be integrally manufactured therewith. The device includes first and second tubes disposed longitudinally along the lower portion of the keel of the vessel through which seawater flows during the sailing of the vessel. Each of the tubes includes forward and rearward watertight valves. When the valves are open, water is free to flow through the tubes. When the valves are closed, water will be trapped within the tubes, thus adding the mass of the trapped water to the keel. The mass of the water within the tubes serves to prevent capsize about one of the outriggers of the vessel.

Abstract: An underwater appendage for sailboats, such as a keel or rudder, is fitted with an external shell-like shroud, which is placed around a core portion of the appendage such that the outer shroud forms a deformable water foil which is fastened on both sides of the core near its rear or trailing edge, and which shroud is everywhere else spaced away from the core. This deformable shroud forms a hydrofoil, the leading edge of which can be displaced to either side of the core by means of inflatable bladders placed on either side of the core, thus creating a desired angle of attack for the deformable foil, either to port or starboard. Inflation of the bladder on the windward side of the boat creates an angle of attack to windward and also a bulging of the shrouded water foil on the windward side creating the desired hydrodynamic lift to counter the lateral component of the aerodynamic force on the sail.

Abstract: The present invention relates to an apparatus for the stabilizing of the direction of travel of watercraft. The invention relates specifically to a sword or fin for sailboards. In order to allow the wind-profile like shape of the apparatus to adjust itself in accordance with a prevailing velocity of flow or a prevailing flow thereagainst, the apparatus comprises two deformable side walls which are mounted to a rigid and stiff center wall exclusively at an area located at the leading edge thereof in relation to the direction of flow. These side walls enclose together with the two oppositely arranged surfaces of the center wall two void spaces. Depending on the prevailing pressure situations between the luff side and the leeward side, an optimal hydrodynamic flow profile is automatically generated. According to preferred embodiments, the trailing edge of the apparatus comprises vacuum pumps which communicate with the void spaces, which vacuum pumps are present in form of water jet pumps.

Abstract: The object of this invention is an element, such as a rudder, and aircraft wing, a boat keel, a hydrofoil or an airfoil or the like, which is adapted to move through water or air and which is so designed that the water or the air is allowed to enter at the upstream edge of the element into and through a hollow space within said element and to leave said element at the trailing edge thereof, said hollow space within said element being divided into two halves by a central longitudinal partition (6) within said element, such that said element on either said of the said central partition (6) has a flow gap which, optionally, is divided into parallel passages by transverse partitions (4a, 4b, 5a-5c), the arrangement being such that the flow of water or air through and out of the gap between the central partition (6) and that side of the element which, in response to the angular deflection or profile, forms the suction side of said element, will be substantially larger than through the other gap.

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 sailing craft having hydrodynamically shaped catamaran hulls and tapered configuration rudder assemblies attached to each hull. Low draft keels are attached to the fore one-half bottom portions of the hull and a pitch-sensitive variable camber mast and mail sail assembly is rotatably mounted on a cross-beam framework which interconnects the two hulls. The mast is constructed and rigged to bow with respect to the longitudinal plane of the sailing craft which passes through the roll axis in response to a high velocity wind force. The bow decreases as the wind velocity decreases and the mast rotates to form a camber adjustment through use of battens attached to the mail sail sheet(s). The rudder assembly and control bungy cords and lines permit selective raising and lowering and automatic raising upon contact with underwater obstacles. The deck structure provides for quick dismantling and ease of sailing.

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 motor boat hull is provided with a longitudinal channel formed in the central portion of the underside surface, starting at an intermediate location and terminating at the stern. Exhaust gases from the propulsion engine are introduced into the forward portion of the channel and the gases flow toward the stern thereby reducing the contact of the hull with the water and reducing the hull-to-water friction levels and reducing the power required to propel the hull at a given speed.

Abstract: A centerboard snubber is disclosed for use in a sailboat equipped with a weighted centerboard or a swing keel in order to prevent the weighted centerboard or swing keel from retracting into its trunk under the force of gravity, the force of passing water, or such forces combined, during excessive heeling of the sailboat in either direction thereby retaining the stability and self righting capability of the sailboat provided by the extended weighted centerboard or the extended swing keel.

Abstract: A convertible sailboat/motorboat is disclosed which has capability for displacement movement under maximum speeds typical of the maximum for displacement boats as a function of their size, capability for semi-planing of the hull under sail propulsion, and capability for planing of the hull under motorboat propulsion. The key features are an extremely light hull weight, an engine located approximately amidships, and a deep retractable keel with an upper trim tab which upon retraction into the hull creates a large shift of center-of-gravity rearward for the boat. The keel is hinged at a point above and to the rear of the keel which imparts a large rear movement of the keel weight for motorboat operation upon its retraction. Performance under displacement sailing is uniquely enhanced with the combination of a low-weight, deep keel and the keel trim tab in the upper portion of the keel where slip reaction is generated with the addition of a minimum of extra heeling moment to that generated by the sails.

Abstract: A marine vessel having a hull with a hollow keel, generally of a non-metallic material, and an engine cooled by a closed-loop, fresh water circulating cooling system. The keel is formed as a hollow keel chamber which has entry and exit apertures for circulating sea water through the chamber. A portion of the fresh water cooling system passes through the hollow keel chamber in heat exchange relation to the sea water providing a simple and efficient heat exchanger for cooling the engine.