Abstract: A ship designed to achieve high speed through the use of multiple, low wave-making resistance, submerged hullform pods is constructed for stable operation during maneuvers with and without a payload. Movable fins on the submerged hullform pods are constructed and are operable to provide the turning and to counteract an inertial moment produced by an elevated center of gravity of the ship so that the ship turns flat or rolls into a turn and does not roll out of a turn. A load balancing pod is movable fore-to-aft and side-to-side to balance the amount and the location of varied payloads on the ship. The movement of the fins may be a tilting movement, or each fin can be maintained at a set angle but extendable out of and retractable into a related pod to create the amount of side force needed for maneuvers and/or to control the amount of lift that might be needed during operation of the ship.

Abstract: A modified mast and keel system for a sailing vessel. The mast is gimbaled to the hull, so that it can move in a pitch roll. A downward extension of the mast pivotally connects to a winged keel. An aft strut also pivotally connects to the hull and pivotally connects to the winged keel. The hull, the mast extension, the winged keel, and the aft strut combine to form a traditional four bar linkage which is used to adjust the angle of attack of the winged keel with respect to the vessel. The winged keel moves with the mast in pitch and roll. It also includes a hydrofoil having an angle of attack which can be changeable in response to the pitching of the mast. This hydrofoil thereby generates downforce which counteracts the lifting forces created by the mast. It also creates lateral forces to counteract the sideslip of the vessel.

Abstract: A hydrofoil (1) comprises a bottom (23) formed with two front and rear steps (3 and 4), and a strut (31) supporting a submerged hydrofoil (21) arranged between the two steps (3 and 4). The strut (31) can be switched between a storage state and a navigation state by its forward-and-backward rotation. A threshold value of dynamic lift (F) obtained by the hydrofoil (21) can be established arbitrarily, and the dynamic lift can be held to the set value by keeping the strut (31) in the navigation state correspondingly to the established threshold value of hydrofoil-dynamic-lift, thereby enabling the dynamic lift to be held at the established value during navigation. Moreover, based on draft (WL) or trim angle (TR) during the boat-berthing, a set value of hydrofoil-dynamic-lift and a set value of tilt angle of a propulsor (22) or a flap (22a) attached to the rear of hull can be accommodated.

Abstract: A simple, lightweight, manually-controlled device for stabilizing and increasing the performance of small, sail-assisted watercraft, containing a single moving part and comprising a curved spar or iako (1) joining a main hull and a single outrigger hull or ama, a tubular shaft (2) with a handle (7) at one end and an “L” shaped hydrofoil (5 and 6) at the other end. The tubular shaft (2) is joined to the iako (1) by two or more struts (3) that are fixed to the iako (1) at their upper ends and have machine screws (8) or sleeves (4) at their lower ends by means of which the tubular shaft (2) is permitted to rotate around its longitudinal axis and is prevented from moving horizontally in relation to the curved iako (1), thereby making the entire assembly a truss or girder that resists vertical distortion or flexion.

Abstract: A sailing craft including a single hydrofoil assembly, an aerofoil assembly, and a hull assembly with a rigid beam interconnecting the hydrofoil assembly, the aerofoil assembly, and the hull assembly. The hull is separate and displaced from the hydrofoil assembly and is, in use, supported above the water by the rigid beam. The hydrofoil assembly, the aerofoil assembly, and the hull assembly are preferably interconnected such that the hydrofoil assembly and the aerofoil assembly are disposed at opposite ends of the rigid beam and the hull is connected to the beam therebetween.

Abstract: Presented is a high efficiency high-speed boat or ship that has multiple hulls. These multiple hulls can include recesses in their undersides that are supplied with pressurized air to form supporting air cushions. There is a support and stability adding hydrofoil disposed between two of the multi-hulls and one trimmable hydrofoil mounted to the transom in the preferred embodiment of the invention. There are water deflecting steps forward of recesses inset in one or more sides of the multi-hulls where such recesses are preferably above the sidehull chines.

Abstract: A boat has one or more jet pumps with appropriate water intakes and jet nozzles to drive the boat and one or more outboard motors to drive the boat. The boat may also have one or more hydroplane fins allowing the hull of the boat to be lifted out of the water for fast hydroplaning motion. The hydroplane fins are extendable and retractable and the one or more jet pumps and/or outboard motors are movably mounted and can be lowered so as to be disposed below the water level in efficient operating position even when the hydroplane fins are extended and the hull of the boat is lifted out of the water for fast hydroplaning motion.

Abstract: Presented is an air lubricated ship that offers improved efficiency and stability over the prior art. Features of the preferred embodiment of the invention include: 1) a submerged bow that is generally proximal in depth to the stem, 2) a hydrofoil at the bow that not only adds stability but also allows the pressurized air layer(s) to extend further forward under the hull thereby reducing wetted area friction, 3) use of more than one air layer in series which is generally accomplished by water deflecting steps at the air layers forward portions, 4) special positioning of propulsors so that they do not interfere with the air layer(s) by aspirating pressurized air from the air layer(s), 5) optional outrigger hulls to aid to stability and to also increase useful deck area, and 6) optional configurations that allow for use of more than one air lubricated hull where such hulls are connected by structure in catamaran or other arrangements.

Abstract: A high efficiency extremely stable marine vehicle that is connected to and supported by submerged supporting structure(s) is presented. The submerged structure(s) are normally airfoil shaped to insure maximum efficiency and are, in the preferred embodiments, air lubricated on their undersides by pressurized air to reduce wetted area frictional effects. Propulsor(s) take in water from the boundary layer adjacent the upper surfaces of the submerged supporting structure(s) which provides boundary layer control and also enhances the efficiency of the propulsor(s).

Abstract: Presented is a high efficiency high-speed boat or ship that has multiple hulls. These multiple hulls can include recesses in their undersides that are supplied with pressurized air to form supporting air cushions. There is a support and stability adding hydrofoil disposed between two of the multi-hulls and one trimmable hydrofoil mounted to the transom in the preferred embodiment of the invention. There are water deflecting steps forward of recesses inset in one or more sides of the multi-hulls where such recesses are preferably above the sidehull chines.

Abstract: A water sport device for supporting a seated human rider while the rider and the device are towed behind a powered water craft, including an elongate board to which a seat and foot holder are secured, an elongate hydrofoil extending downward from the board and a planing blade secured to the hydrofoil generally parallel to the board so that the planing blade provides essentially no lift when the board is horizontal. The improvements comprise an adjustable rear blade to permit the rear blade to be manually adjusted to increase or decrease the space between the blades; and the rear blade is shaped to have an angle which slopes downward from the top surface to its leading edge and a thin rear trailing edge.

Abstract: A monohull keel sail boat is provided with a bow foil structure, a keel foil structure and a stern foil structure. The bow, keel and stern foil structures have foils with may be moved to provide a variable angle of attack and thus variable lifting forces. The stern foil structure has a ladder foil arrangement and includes vertical struts to provide steering control thus replacing a conventional rudder. The three foil structures work in concert to lift the hull of the boat, but not the keel, completely out of the water so as to provide near listless sailing.

Abstract: A Small Waterplane Area MultiHull vessel having an upper hull platform located above the design water line of the vessel which is maintained above the surface of a body of water by at least two cylindrical submerged hulls joined thereto by supporting struts. A buoyant core material is contained between inner and outer walls of the submerged hulls which define a cylindrical space in which a rotary propulsive means may be housed. In one embodiment, an engine means is situated on the upper hull platform and is joined to the rotary propulsive means through a work translating means which converts the output of the engine to rotary motion of the rotary propulsive means to provide a propulsive force.

Abstract: The improved flying ski is designed to be towed behind a conventional powered watercraft utilizing a standard ski tow rope or similar device having a handle that can be held by a human rider. In use, the rider is seated on the seat of the flying ski and towed by the watercraft. The improved flying ski comprises an elongate board and a seat that extends generally perpendicular to and upward from the board to support the seated rider's buttocks. The rider's legs extend toward the front of the board and are secured by a pair of foot holders that attach to the board. An elongate strut extends generally perpendicular to and downward from the board and couples the seat to a planing blade. The planing blade advantageously has a front blade and a rear blade interconnected by a fuselage. The improved flying ski accommodates a variety of rider skill levels by incorporating a mechanism and system that allows the rider to selectively adjust performance characteristics of the ski.

Abstract: The improved flying ski is designed to be towed behind a conventional powered watercraft utilizing a standard ski tow rope or similar device having a handle that can be held by a human rider. In use, the rider is seated on the seat of the flying ski and towed by the watercraft. The improved flying ski comprises an elongate board and a seat that extends generally perpendicular to and upward from the board to support the seated rider's buttocks. The rider's legs extend toward the front of the board and are secured by a pair of foot holders that attach to the board. An elongate strut extends generally perpendicular to and downward from the board and couples the seat to a planing blade. The planing blade advantageously has a front blade and a rear blade interconnected by a fuselage. The improved flying ski accommodates a variety of rider skill levels by incorporating a mechanism and system that allows the rider to selectively adjust performance characteristics of the ski.

Abstract: A hydrofoil stabilizer fixed to an underwater hull and provided with a pair of pivotally deflectable control flaps through which surface lift on the stabilizer is controlled, is provided with trailing edge tabs on both of the flaps that are pivotally deflected in the same direction to further offset and thereby improve recovery from surface jam inducing lift force on the stabilizer which adversely affects maneuvering control.

Abstract: The invention provides a hydrofoil equipment water craft comprising at least one hull member, terminating at a bow and a stern, a front hydrofoil member arranged in the zone of the bow of the hull, at least partially below the hull; and a rear hydrofoil member positioned to the rear of the longitudinal center of gravity (LCG) of the hull, the front hydrofoil member being at least partially offset transversely relative to the rear hydrofoil member so that the front hydrofoil or rear hydrofoil are at least partially disposed in separate longitudinal flow streams.

Abstract: A mechanism and method for dynamic trim of the floating position of a fast moving, planing or semi-planing ship hull is suggested, wherein a fully submerged hydro foil (1) is pivotally arranged in a stem portion of the ship and continuously adjustable relative to the angle of attack of the hydro foil for generating a wave, the wave having a length, a width and a depth related to the length, the tonnage and the cruising speed of the ship, wherein the hydro foil is designed relative to the wave so that the wave width is controlled by a span width (a), the wave length is controlled by a chord length (b), and the wave depth is controlled by a load (p) of the hydro foil.

Abstract: An aircraft-like body is provided with a keel that extends below and to the rear of the main body. The keel is provided with a large horizontally extending hydrofoil which produces a positive lift. The keel is further provided with a smaller hydrofoil which is located aft of and below the positive life hydrofoil and which produces a negative lift. The negative lift hydrofoil is located both aft of and below that which produces the positive lift. The downward force which is produced by the trailing hydrofoil produces a cranking action which produces a moment and applies a lifting force which, as the vehicle proceeds through the water, lifts the nose of the vehicle and impart an aircraft lift-like flying type of sensation to the operator.

Abstract: A sloped hydrofoil (22) is mounted to the bottom of a sailboard or surfboard vertical strut (26) using a hinge joint (24). Hinge joint (24) allows reversal of the slope of sloped hydrofoil (22) in response to a hull (30) side slip. Efficient sloped hydrofoil (22) supports a portion of craft weight to reduce hull (30) drag.

Abstract: A wake control apparatus for adjusting the trim of a watercraft to selectively raise and lower the level of the wake produced by the watercraft. The apparatus comprises a pair of hydrofoils which are pivotally connectable to the watercraft in spaced relation to each other. Mechanically coupled to respective ones of the hydrofoils is a pair of actuators which are connectable to the watercraft. Each of the actuators is operative to pivotally move a respective one of the hydrofoils between neutral, first and second positions. The apparatus is attachable to the watercraft such that each of the hydrofoils is moveable by a respective one of the actuators about an axis which extends in non-perpendicular relation to the longitudinal axis of the watercraft.

Abstract: A wake control apparatus for adjusting the trim of a watercraft to selectively raise and lower the level of the wake produced by the watercraft. The apparatus comprises at least one hydrofoil which is pivotally connectable to the watercraft, and at least one actuator which is mechanically coupled to the hydrofoil and connectable to the watercraft. The actuator is adapted to selectively move the hydrofoil between first and second positions. When the apparatus is connected to the watercraft and the watercraft is propelled within the water, the movement of the hydrofoil toward the second position causes the aft end of the watercraft to be drawn downwardly into the water to increase the level of the wake produced thereby. The movement of the hydrofoil toward the first position causes the aft end of the watercraft to be elevated within the water to reduce the level of the wake produced thereby.

Abstract: A sloped hydrofoil (22) is mounted to the bottom of a sailboard or surfboard vertical strut (26) using a hinge joint (24). Hinge joint (24) allows reversal of sloped hydrofoil (22) slope in response to a hull (30) side slip. Efficient sloped hydrofoil (22) supports a portion of craft weight to reduce hull (30) drag.

Abstract: Hinge apparatus which includes first and second hinge members (12, 14) arranged for relative rotation about a hinge axis (18), and fluidic actuator apparatus (24). The fluidic actuator apparatus includes a force transfer member (22) having a first end attached to the first hinge member at an anchor location spaced from the hinge axis, and expandable pillow (25) apparatus associated with the force transfer member and operative to expand when exposed to a fluidic pressure thereby to apply a force along the force transfer member to the first hinge member so as to cause rotation of the first hinge member relative to the second hinge member in at least a first direction.

Abstract: Disclosed is a construction applicable to stern drive and outboard types of power boat propulsion units for enhancing the performance normally provided by the customary trim/tilt capabilities designed into the units. At a critical juncture in the trim/tilt operation, the present device automatically "kicks in" and by intercepting only a predetermined portion of the propeller backwash provides an almost immediate stern up/bow down result without noticeable speed retardation. The device lends itself either to kit form or to factory installation.

Abstract: A watercraft comprises a hull having an upper surface, a lower surface, a bow and a stern. Spaced from the underside of the watercraft at the bow end is a pair of outwardly extending arms rotatably supporting discs. Likewise at the stern of the hull, a pair of arms rotatably supports an additional pair of discs. A multitude of such discs may additionally be provided with bearings. Alternatively, the discs may be mounted upon a ball joint arrangement for rotation and pivoting throughout a preselected range. Each disc is acutely angled from a horizontal reference plane. When the watercraft moves in a forward direction, the discs will rotate. As a result, the relative contact velocity between an underside portion of the discs and the water is substantially reduced as compared to a surface which is fixed to the watercraft. The contact friction is thereby reduced resulting in high speed capabilities of the craft with relatively low powered propulsion units.

Abstract: A method and an assembly are provided for mounting a pair of hydrofoils to an outboard engine without drilling holes or otherwise defacing the anticavitation plate of the engine. The assembly includes a mounting plate, an adaptor, and a pair of hydrofoils. The hydrofoils are mountable to the outer edge portions of the mounting plate. In use, the counter-rotation tab of the engine is removed and then replaced by the adaptor. The mounting plate, if not already secured to the adaptor, is coupled to the adaptor. The hydrofoils are then mounted to the opposing edges of the mounting plate. A pair of reinforcing brackets may be secured to the mounting plate such that they extend over the edge portions of the cavitation plate. The forces generated upon the mounting plate will accordingly be distributed to the anti-cavitation plate as well as the adaptor. The hydrofoils employed in the assembly preferably include rudders, which obviate the need for the counter-rotation tab replaced by the adaptor.

Abstract: A hydrofoil member for a sailboat of the type having a single hull with no fixed ballast includes an elongate arm portion which extends laterally outwardly away from the sailboat along a generally horizontal plane when in use. The arm portion has an upwardly-facing surface, a downwardly-facing surface, and an outer end portion which flares upwardly relative to the horizontal plane. The hydrofoil member further comprises a pontoon element mounted on the downwardly-facing surface of the arm portion at the outer end portion. The pontoon element is adapted to engage and displace water when in use for stabilizing the sailboat. The arm has is capable of being retracted to stow the hydrofoil member in a parallel position against the hull when not in use.

Abstract: A sloped hydrofoil (22) is mounted to the bottom of a sailboard or surfboard vertical strut (26) using a hinge joint (24). Hinge joint (24) allows reversal of sloped hydrofoil (22) slope in response to a hull (30) side slip. Efficient sloped hydrofoil (22) supports a portion of craft weight to reduce hull (30) drag.

Abstract: A twin-hull boat equipped with a pair of transverse hydrofoils 4 and 5 which are respectively secured to the bottom surface of twin-hull structures 3A and 3B adjacent the stem and stern. A pair of auxiliary wings 6A and 6B are installed opposite to each other at predetermined positions on the internal wall surfaces of the twin-hull structures 3A and 3B mutually facing the hull center line and at a predetermined height between the upper water line formed in the course of low-speed cruising and the lower water line formed in the course of high-speed cruising. The twin-hull boat incorporates a postural angle regulating device 15 to properly regulate the postural angle of the auxiliary wings 6A and 6B by causing them to pivot about a horizontal axis.

Abstract: A hydrofoil craft has a hull supported above a water surface by a foil connected to the hull by means of a support arm. In accordance with one form of the invention, the support arm enables the foil to move up and down with respect to the hull in concert with upgusts and downgusts of water surrounding the foil so as to maintain the hull at an approximately constant elevation. In accordance with another form of the invention, the support arm is supported by the hull for pivoting about a longitudinal axis extending in substantially the fore and aft direction of the hull. When rolling forces act on the foil, the support arm can pivot about the axis from a vertical position in response to the rolling forces while enabling the hull to remain substantially level.

Abstract: A passively controlled hydrofoil supported planning watercraft having a conventional hull with an integrally formed step. The watercraft includes a centrally located, fully submerged main lifting foil. The main lifting foil is fixed and non-movable, and is attached to the hull along the centerline keel such that its line of action acts substantially through the longitudinal center of gravity of the watercraft. The watercraft further includes a rearwardly located stabilizing foil fixed to a stabilizer strut which is pivotally attached to the stern of the watercraft. A stabilizer strut so attached pivots fore and aft to control watercraft trim angle. Additionally, the stabilizer strut is rotatable about a substantially vertical axis for steering and roll control, and includes a trailing edge upper rudder for yaw control.

Abstract: The invention is a displacement boat hull having the outboard surfaces of its wetted portion designed with a deep-V shape, and having at least one pair of retractable hydrofoil fins positioned in respective pockets along those outboard surfaces at a predetermined distance above the keel. When extended, the fins are positioned at fixed angles relative to the hull, and at least one pair of fins is positioned in proximity to the stern. In a preferred embodiment, a conventional deep-V semi-displacement hull is modified to increase the conventional maximum draft with an unusually steep angle (at least 30.degree.-40.degree.) for the initial deadrise from the keel upward toward the chine; and at least two pairs of fins are disposed on opposite sides of the hull, with an aft pair being positioned in proximity to the stern and another pair being positioned forward of the stern pair, preferably just forward of the boat's center of balance.

Abstract: A device for permitting an outboard motor boat to operate in shallow water, comprises a first support for securing to a transom of a boat and extending rearwardly therefrom; a keel secured to the first support and extending downwardly therefrom and rearwardly from the transom; a vertically adjustable motor mount for supporting an outboard motor with a propeller housing having a leading surface, the motor mount for positioning the motor in a raised position to permit the boat to operate in shallow water and a lowered position in normal-depth water; and the keel includes a rear edge substantially parallel and adjacent to the leading surface of the propeller housing when the motor mount is in the raised position.

Abstract: A watercraft employs three or more supercavitating hydrofoils. The elements that connect the hydrofoils to the hull may flex to thus raise or lower the hydrofoils relative to the hull. The relative motion between the hydrofoils and the hull is dampened by shock absorbers or the like. A control system operated by the pilot may apply forces tending to raise or lower the hydrofoils relative to the hull. The stern hydrofoil is mounted on a support that also carries a power driven propeller and a rudder.

Abstract: An improved hydrofoil system is provided for boats with planing-type hulls Two hydrofoils, one mounted adjacent to each chine, are provided in a submerged position. The attack angle of each hydrofoil is controlled independently by a hydraulic cylinder or the equivalent thereof. Because both positive and negative attack angles of each hydrofoil may be presented, the hydrofoil system disclosed has the ability to raise and lower the bow, raise and lower the stern, provide lateral stability and also act as an auxiliary rudder by rotating the boat about its longitudinal axis. The submerged hydrofoil system is intended for use with boats with planing-type hulls.

Abstract: A hydrofoil craft which possesses at least one hull, at least one support arm which extends from said hull into the water and which is connected to the hull, at least one foil attached to each support arm, and preferably at least one shock strut per support arm which pivotally connects said hull to the support arm, so that said shock struts allow the support arm and the foil to move in concert with the upgusts and downgusts of water velocity located near the foil so as to enable said hydrofoil craft to maintain approximately constant lift. The principles involved are also applicable to aircraft of the "wing in ground effect" type which is designed to fly close to the water's surface so as to take advantage of the favorable aerodynamic effects of the water's proximity.

Abstract: A hydrofoil sailboard comprising a conventional sailboard, without the usual tail skeg, equipped with two hydrofoils arrayed in a canard configuration, the combined lift of the foils being sufficient to hold the board clear of the water at operational speeds. The main foil, mounted beneath the rear of the board is designed to ride fully submerged and to support the bulk of the weight of the board and sailor. The much smaller canard foil, mounted beneath the front of the board is designed to ride at or near the water surface, and its purpose is control and balance. The main foil is connected to the board by a supporting foil which is provided with ventilation fences. The canard is rigidly connected to the board by a support comprising a rod about which a streamlined fairing is free to swivel. A seal between the fairing and the rod prevents airflow to the canard along the inside of the fairing.

Abstract: A strut leading edge extension for a marine vehicle has an upper hull, a strut, a lower hull, and a foil. The strut leading edge extension includes a device for defining an extended strut leading edge, the device being adjustable to a plurality of positions including a fully retracted position and a fully extended position. The defining device is disposed at a front portion of the strut. An actuator moves the defining means to a plurality of positions; wherein a directional dynamic stability of the marine vehicle may be controlled by the position of the defining device.

Abstract: A watercraft having positive static buoyancy is provided which is operable both as a hydrofoil and submersible vessel. It is generally shaped in the form of a dolphin or porpoise, with the equivalent of fins acting as both navigation and attitude control mechanisms. Pectoral or forward fins provide hydrofoil struts when manipulated into one position and then are operable as diving planes when displaced into an alternate position. A dorsal fin provides supplemental rudder control. A pair of flukes or rear fins provide for pitch and/or dive control while the vessel operates in the submerged mode. These fins and a propulsion system are either manually or computer controlled by way of hand held joysticks and foot rudders. Submerged operation is achieved with an internal combustion motor by including an air compressor and air storage tank(s) with an air intake arrangement having automatically operable devices serving to open and close an air intake in response to exposure to water.

Abstract: A hydrofoil for watercraft is provided. The hydrofoil includes a generally flat body including an upwardly extending wing for providing low speed torque control and rudders extending from the bottom surface of the body to provide high speed torque control. The hydrofoil is adapted for mounting to an anti-cavitation plate. The depth of the hydrofoil can be controlled through the use of shims or a bracket including an offset arm to which the hydrofoil is mounted. The angular position of the hydrofoil is adjustable in the horizontal plane, thereby allowing the rudders to compensate for the lateral torque produced by a propeller.

Abstract: A windsurfer board is formed, towards the tail end thereof, with a slot in which a box is fitted. The box provides a mounting for a fin which is movable, while in use, relative to the board in such manner as to permit simultaneous adjustment of the inclination of the fin relative to the board and of the extent by which the fin projects downwardly beneath the board. The mounting for the fin includes a bracket pivotally connected to the box and to the fin.

Abstract: The present invention relates to an apparatus designed to launch a sailboard out of the water while the sailboard is being sailed on the water. The apparatus comprises launching means including a flap which is submergible in the water and pivotally supported at one end of the flap near the bottom of the sailboard. An angle of attack of the flap relative to the water is varied by a positioning means. The submerged flap is thus presented at an oblique angle to the incompressible water which thus acts as a ramp to launch the sailboard out of the water. In an alternative embodiment, a hydrofoil wing acts to lift the sailboard relative to the water surface.

Abstract: The invention relates to a pair of five-sided hydrofoils for use in conjunction with the lower unit of a conventional outboard motor. The invention improves the stability of a boat and reduces the time required for a boat to achieve a planar configuration with respect to the surface of a body of water. The hydrofoils include leading edges having upturned angular portions and trailing edges having downturned angular portions. The leading and trailing edges are designed to simultaneously apply a lifting force to the stern and a downward force to the bow of a boat as the boat is propelled through the water. The invention improves the performance, safety, comfort, and useful life of a boat and a conventional outboard motor.

Abstract: An asymmetrically arranged hydrofoil and propeller system is disclosed for improving the speed and lift of watercraft such as amphibious vehicles. When the vehicle is propelled through water by propellers, a downwash of water from the upper surface of the asymmetrically arranged hydrofoils is intercepted by upwardly moving propeller blades which improve the speed, lift and efficiency of the watercraft.

Abstract: A combined fixed hydrofoil and trolling plate where the trolling plate is moveable releasably to a horizontal position to enhance the hydrofoil effect of the fixed hydrofoil.

Abstract: A rectractable hydrofoil for watercraft wherein a linking mechanism connects all hydrofoils to a retaining assembly. The application of an external force to a hydrofoil above a threshold causes the release of the retaining means without requiring the reaction of the operator. A control assembly within the hull is utilized by the operator to complete the movement of the hydrofoil to an aft retracted position. The retaining assembly includes a releasable securing means for maintaining the hydrofoils in the retracted position.

Abstract: A boat stabilizer for attachment to the lower drive unit of a boat motor. The stabilizer comprises a first lifting member having a first interior side wall for positioning adjacent to a first side of the drive unit and a first arm portion for extension around the drive unit, and a second lifting member having a second interior side wall for positioning adjacent to a second side of the drive unit and a second arm portion for extension around the drive unit toward the first arm portion. The second interior side wall is spaced from and opposes the first interior side wall forming a slot therebetween for receiving the drive unit. The first and second arm portions are removably attached together and selectively movable toward and away from each other for varying the width of the slot. The ability to vary the width of the slot for receiving the drive unit allows the stabilizer to be adjusted to fit virtually any conventional outboard or inboard/outboard boat motor.

Abstract: The wave making resistance on a proceeding ship can be greatly decreased by providing the ship hull with at least one pair of fins mounted on the hull extending above and below the draft line, each fin being fixed at the front end line and the rear end of the fin outwardly extending making a certain fin-mounting angle of 2 to 25.degree. with the hull surface.

Abstract: A multi-hulled sailing vessel is provided with a pair of aileron foils that are mounted outboard from each of two sponsons that are rigidly joined to a central main hull. The aileron foils are rotatable about axes that are inclined toward each other when deployed. Each of the sponsons is provided with a mast carrying a sail. The masts are coupled together by a pair of transverse stabilizing struts. The masts are each supported by separate shroud systems. The vessel is equipped with load sensing and foil control means coupled to at least some of the shrouds and to the aileron foils so as to rotate the aileron foils about their axes responsive to loads in the shrouds. A rudder at the rear of the central main hull is provided with a transversely mounted elevator foil which is also rotated about an axis transverse to the rudder responsive to loads in the shrouds. The foils and the rudder are mounted for rotation relative to the sponsons and the central main hull and can be brought entirely out of the water.