Abstract: A fin assembly includes a fin body and a fin holder. The fin holder has an elongated channel, a pair of opposing slots, a pair of front guiding grooves and a pair of rear guiding grooves. The pair of front guiding grooves are defined in the opposing sidewalls of a front section of the elongated channel at a horizontal level, and misaligned with a bottom of the elongated channel. The pair of rear guiding grooves are defined in the opposing sidewalls of a rear section of the elongated channel above the horizontal level, and are flush with the bottom of the elongated channel Besides, the fin holder defines in its rear wall a horizontal hole with a cross section large enough to cover a space between the pair of rear guiding grooves.

Abstract: A retractable fin system having a retractable fin and fin box is disclosed. An example retractable fin system includes a housing insertable into an opening in a watercraft board. The example retractable fin system also includes a retractable fin. The example retractable fin system also includes a bias to maintain the retractable fin in a default outward position from the housing. The bias retracts the retractable fin into the housing on contact with an outside force.

Abstract: The present application is directed to a selectively deployable fin system which includes at least one housing positioned within a body of a standup paddleboard, the housing defining at least one housing passage therein, at least one actuator is positioned within the housing. The actuator is configured to be operable by a user positioned on the standup paddleboard or similar watercraft during use. At least one linkage system, in communication with the actuator, is positioned within the housing. In addition, at least one fin is in communication with the actuator via the linkage device. The fin is configured to be selectively positioned within the housing in a retracted configuration and selectively extending from the housing in a deployed configuration.

Abstract: A hydrofoil trim tab for use with each of a pair of seaplane floats, each tab including a substantially planar shaped body secured to an inside facing location of each float such that a pair of tab bodies are arrayed in opposing and inwardly directed fashion relative to the floats. Each tab is further constructed as a two piece article, a first portion being either mechanically secured or welded to the surface of the float, with a second portion being releasably/breakaway attached to the first portion, such as by frangible fasteners engaging a slidably connection location between the portions. In this fashion, inadvertent breakage of a trim tab at the frangible location will prevent damage to the float.

Abstract: This invention provides improvements in the efficiency of a sailing vessel through the use of flaps, hydrofoils, or members on the keel of a sailing vessel. One or more are positioned at the top, or root of the keel of the vessel, which primarily generate a force in the windward direction to provide a counter-leeward drift force. One or more are located at the bottom, or tip of the keel of the vessel, which primarily generate a force in the leeward direction to provide a counter-heeling moment. Among other benefits, operation of these flaps, hydrofoils, or members during sailing increases the vessel's efficiency, in particular its velocity made good. Further, since they are mounted on one appendage, sailing vessels of a rudder and keel design can be equipped with counter leeward-drift and counter-heeling attributes without the need for additional appendages.

Abstract: A canting ballast twin foil (CBTF) sailing yacht constructed according to the invention includes a sailing hull, a laterally moveable ballast suspended beneath the hull that provides a counter heeling force when the yacht is underway, and fore and aft foils that provide improved leeway control and ballast. Components are included for at least partially retracting into the hull at least one of the ballast-supporting strut, the fore foil, and the aft foil.

Abstract: A Rotatable Keel Appendage comprising a conical hollow support fixed to a sailboat hull into which is juxtapositioned a rotatable cone member which supports a fin keel carrying a heavy ballast bulb. The rotatable cone member has a threaded shaft at its peak which has a diameter greater than the thickness of the fin and is lockable to the fixed appendage conical hollow support by a nut on the threaded shaft. In another embodiment, the rotatable cone member carries two fins, in either spaced parallel relationship or in spaced aligned relationship. Mathematical Formulas for Energy Balance are developed to establish that a tacking sailboat with the appendages in the Specification will hydrodynamically generate forces to both decrease the leeward drift and increase the forward velocity of the hull. Methods for sailing more quickly to reach a windward destination are set forth using the appendages in the specification.

Abstract: A wind surfing apparatus formed with a hull supporting a mast and sail includes a removable daggerboard having a weighted mass in a lower end portion thereof to lessen the tendency of the hull to be unstable or flip during use. The weighted mass may either be integrally molded into the daggerboard lower portion such as with fiberglass materials, or may be releasably attached to the daggerboard to allow for selection of a desired amount of weight. The wind surfer apparatus further includes a ratchet mechanism for controllably selecting and maintaining a desired orientation of the daggerboard stabilizer relative to the hull during use. A hinge connects the mast to the hull through two separate connecting mechanisms. One of the connecting mechanisms between the hinge and mast permits pivotal movement of the mast/sail unit in the plane of the sail only. The other connecting mechanism between the hinge and hull enables rotation of the mast/sail unit about the mast axis only.

Abstract: A sailing yacht, in addition to its ballast keel (2), has at least one winged keel ( ) which optionally also carries ballast. Both ballast keel (2) and winged keel (1) are mounted to swivel on the hull of the sail ship around an axis aligned essentially in the longitudinal direction of the sail ship. Thus, by swivelling ballast keel (2) the righting moment is changed, for example, increased. By swivelling winged keel (1) its lateral plane part can be changed and thus can be kept large even when the sailing yacht is heeling.

Abstract: A wind surfing apparatus formed with a hull supporting a mast and sail includes a removable daggerboard having a weighted mass in a lower end portion thereof to lessen the tendency of the hull to be unstable or flip during use. The weighted mass may either be integrally molded into the daggerboard lower portion such as with fiberglass materials, or may be releasably attached to the daggerboard to allow for selection of a desired amount of weight. The wind surfer apparatus further includes a ratchet mechanism for controllably selecting and maintaining a desired orientation of the daggerboard stabilizer relative to the hull during use.

Abstract: A movable centerboard for water craft capable of multiple settings having an upper position within the hull, a lower position at full depth below the hull and multiple settings therebetween such that the system is adapted to receive and operate the centerboard from above. The centerboard and centerboard well are adapted to operate in concert whereby, multiple board positions may be utilized. Introduced from above, the centerboard slides down to an upper position within the hull, from here it can either pivot up completely into the well or it can continue to slide diagonally to its maximum depth whereupon it can pivot to the vertical lower position. The selected positions of the centerboard are held in place by a control pressure wedging device from above, whereupon being struck from below will release allowing the board to pivot and transverse up into the well.

Abstract: A dagger board bearing for sailboards, developed with the objective of improving sailing properties, exhibits a dagger board casing (4) inserted in a sailboard (1) wherein a dagger board (5) introducible from above is pivotably supported with a first handle (6) projecting beyond the topside of the board (5). An external pivot pin (12) in the zone of the top edge (13) of the dagger board (5) and an internal pivot pin (14), offset with respect to the external pivot pin (12) are molded to a top section (11) of the dagger board (5). The pivot pins (12, 14) are arranged on one side of the top section (11) of the dagger board (5) with a mutual first spacing (a) in the longitudinal direction of the dagger board (5) and with a mutual second spacing (b) in the transverse direction of the dagger board (5).

Abstract: A retractable steering device for liquid/bulk cargo carrying barges includes a rectangular barge hull having a generally flat bottom and an upper deck and generally vertical port and starboard sidewalls. A cargo hold is contained at the central portion of and within the barge hull for containing a liquid or bulk cargo. Port and starboard wing tanks are positioned respectively between the port and sidewalls of the hull and the cargo hold. A pair of longitudinally extending slots are positioned adjacent the respective port and starboard wing tanks, each defining an opening that communicates at least with the barge bottom to provide an opening to the sea under the barge bottom.

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 lightning protection installation for boats comprising a copper lightning rod mounted on the top of the mast or, in the case of a power boat, mounted on the deck, a copper wire attached to the rod and running downwardly to a point where it is attached to a retractable copper conductor. The copper conductor is retractable through a plastic or fiberglass tube or box molded or inserted in the hull or attached to a centerboard, if available. When the conductor is raised to the passive position, it is protected from the formation of marine growth; and when it is lowered, the conductor provides sufficient wettable electrical conducting grounding surface to conduct the lightning to water ground. Raising the conductor removes the slight drag caused by the grounded conductor.

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: A retractable steering device for liquid/bulk cargo carrying barges includes a rectangular barge hull having a generally flat bottom and an upper deck and generally vertical port and starboard sidewalls. A cargo hold is contained at the central portion of and within the barge hull for containing a liquid or bulk cargo. Port and starboard wing tanks are positioned respectively between the port and sidewalls of the hull and the cargo hold. A pair of longitudinally extending slots are positioned adjacent the respective port and starboard wing tanks, each defining an opening that communicates at least with the barge bottom to provide an opening to the sea under the barge bottom.

Abstract: A supplemental propulsion device for a sailboat or sailboard type water craft including a pivotal centerboard. A pair of propulsion wings that are vertically hinged to one-another and mounted to the lower portion of the leading edge of the centerboard of the craft. Upon the application to the centerboard of a reciprocating pumping action each propulsion wing moves inwardly to a retracted position adjacent the centerboard during forward movement of the lower portion of the centerboard and moves outwardly to an extended position removed from the centerboard during rearward movement of the lower portion of the centerboard. Cables connect the free edge of each of the propulsion wings to the trailing edge of the centerboard to stop the outwardly movement of the wings at a point no more than 90.degree.

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: 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 generally trapezoidal fin (22) is pivotally fastened to a casing which can receive the entire fin, permitting total retraction of the fin. The casing is formed with at least one notch (42) for selectively positioning the fin relative to the casing. In a preferred embodiment, the fin is operated by a lever member (26) which has a knob (50) at its distal end for use in positioning the fin (22) from above.

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 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: A boat hull keel is disclosed which retracts into the boat hull on a fixed pivot. The pivot location is placed above the keel/hull bottom intersection, rearward of the major axis of the fully lowered keel and rearward of the keel trailing edge at the keel/hull intersection. The placement distances are large in terms of the maximum keel chord length. (measured at the keel/hull intersection.) This amounts to a novel location. The location of the pivot allows the keel rotation to create a change in the attitude of the boat hull.

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: 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 sailing craft of the type which includes a floating hull, a mast secured to the hull, a sail mounted on the mast and rudder means, wherein the mast is pivotally mounted with an articulation near but spaced from the base thereof with respect to a substantially horizontal axis, and a pair of mobile fins having variable lift movably mounted, each on a respective one of the port and starboard sides of the hull, and a linkage interconnecting the mast and the mobile fins for actuating the fins such that they act in the water in a manner so as to tend to right the hull under the dynamic action of water on the fins in a direction opposite to the direction in which the mast pivots, and in which the craft would normally heel under the action of the wind to which it is exposed.

Abstract: A sailboat carries a pair of opposed keel sections which are angularly positionable about a common hinge axis, either as a keel unit or individually, by means of compressed air biased hydraulic actuators connected via shock absorbers to the keel sections. An additional hydraulic actuator, adjusts the angle of elevation of the hinge axis, enabling the keel unit or sections, when inclined, to provide hydrodynamic lift. The keel sections, which are hollow and contain radially flowable ballast, are configured, when oppositely horizontally positioned to receive the axles of removable wheels, enabling the boat to be self-trailered.

Abstract: The invention relates to a sailboat with a keel board that is inclinable sideways. A single keel board is resiliently inclinable due to the effect of the water which rotates it about an axis disposed substantially in the vertical plane of longitudinal symmetry of the boat and inclined with respect to the horizontal, rising towards the bows of the boat, so as to provide hydrodynamic lift of the inclined keel board compatible with a movement of the boat along its longitudinal axis. In the case of a boat with two inclinable keel boards, the axes of inclination can converge towards the bows of the boat.

Abstract: A keel assembly or similar fin-like underwater appendage for a boat is provided which is adjustable to adapt its characteristics to the operating conditions of the boat, for example to optimize hull performance of a sailing boat on opposite tacks. The assembly comprises a support and a pair of curved flexible side plates carried by the support and connected at their leading and trailing edges, the curvature of the side plates being adjustable to render the assembly asymmetrical. The leading and trailing portions of the plates are provided by blade assemblies interconnected so as to be oppositely pivotable about axes parallel to leading and trailing edges of the support, the trailing blade assembly having its pivoted axis adjacent its leading edge.

Abstract: The hydraulic system for raising and lowering a heavy keel comprises a cylinder, a piston movable in the cylinder and connected to the keel, and an accumulator for supplying hydraulic fluid at a positive pressure below that necessary to raise the keel against the piston in a direction for raising the keel. A hand pump is provided for supplying hydraulic fluid at a pressure great enough to overcome the weight of the keel. A valve allows the hydraulic fluid to flow either to or from the cylinder. An enlarged flow line communicates the accumulator with the cylinder so that if an external force should cause the keel to raise suddenly, hydraulic fluid would flow rapidly beneath the piston. A gas is provided on the other end of the piston for providing a cushioning effect and restricting the speed at which the keel can be raised. A restricted flow valve is provided in the system for regulating the speed at which the keel can be lowered.