Abstract: A foil structure for providing buoyancy and lift to a floating device is provided. The foil structure comprises an elongated left hand side floating device section and an elongated right hand side floating device section. The left hand side floating device section and the right hand side floating device section are placed at a predetermined distance to a longitudinal axis of the floating device and oriented substantially parallel thereto. A left hand side foil and a right hand side foil protrudes from the left hand side floating device section and the right hand side floating device section, respectively, towards a vertical plane through the longitudinal axis and is oriented at an acute angle to a horizontal plane. A leading edge of each foil intersects the respective floating device section in proximity to a bow portion thereof. Each foil extends along the respective floating device section and terminates in proximity to a stern portion thereof.

Abstract: A marine vessel comprising: at least one buoyant tubular foil; at least one venturi injection ring positioned adjacent to the perimeter of the at least one buoyant tubular foil so as to create a passageway between the at least one venturi injection ring and the perimeter of the at least one buoyant tubular foil, wherein the passageway is characterized by a fore opening, an aft opening, and an intermediate opening disposed between the fore opening and the aft opening, and wherein the intermediate opening is smaller than the fore opening and the aft opening; at least one fluid opening formed in the perimeter of the at least one buoyant tubular foil adjacent to at least one of the intermediate opening and the aft opening; and at least one passageway connecting the at least one fluid opening to a source of fluid.

Abstract: The present invention relates to an underwater foil (1) for a marine vessel of the type floating on water disposed completely below the waterline and extending in the port-starboard direction. The underwater foil (1) comprises a plurality of foil members (2, 3) connected to each other in order to form the underwater foil (1).

Abstract: A drive unit has an engine, an operatively connected driveshaft, a transmission, and a propeller shaft connected to a rotor outside a gear case. A plate, extending above the rotor, is adapted to slidingly receive along a joint axis, an accessory having an accessory joint element which is one of a channel and a protrusion. Extending parallel to the joint axis along a plate joint surface, which is one of a first surface facing away from the rotor and a second surface facing toward the rotor, is a plate joint element, which is the other of the channel and the protrusion, adapted to slidingly interlock with the accessory joint element to thereby prevent displacement thereof in a first direction parallel to the plate joint surface and perpendicular to the joint axis, and in a second direction normal to the plate joint surface. An accessory attachment method is also disclosed.

Abstract: The present invention relates to an underwater floating device (1) characterized in that it comprises: an insert (4) comprising a thermoplastic material and a hollow tube (7), a foam (5) of a thermoplastic material, at least partly covering the insert (4), an outer skin (6) comprising a thermoplastic material formed by injection molding over the foam and configured for being in contact with water during use.

Abstract: A hydrofoil section comprises first and second faces that create, in operation at speeds above a ventilation speed, a ventilated cavity defined by a first cavity face which departs from the first hydrofoil face and a second cavity face which departs from the second hydrofoil face. Each cavity face represents a free surface and each face separating from the said free surface at a discontinuity on that surface, the separated faces forming a continuation of the faces of arbitrary shape and enclosed by the free surfaces without contacting the said free surfaces. Below the speed at which full ventilation occurs the arbitrarily shaped portion of each face is configured to provide a modified flow configuration resulting in changed lift and or drag and or pitching moment under partial, or unventilated operation.

Abstract: The invention relates to a hydrofoil arrangement for a hydrofoil craft with at least one fully submerged lifting wing. The hydrofoil arrangement includes at least two struts pivotally arranged on the hydrofoil craft with each strut being connected to a lifting wing. The struts are arranged with their centers of effort of hydrodynamic forces behind the pivot axes of the struts during forward travel of the hydrofoil craft. They are arranged to pivot relative to the hydrofoil craft when the hydrofoil craft experiences a disturbance in roll-angle. This results in a transversal movement of the hydrofoil craft relative to the water surface during forward travel. The hydrofoil arrangement also increases the roll- stability for a hydrofoil craft.

Abstract: A stern bracket for mounting a drive unit to a watercraft including a transom. The drive unit is pivotable with respect to the stern bracket about a tilt axis. The stern bracket includes a support member for fixing the drive unit to the transom and a water deflector. The water deflector comprises a mounting bracket attached to the support member and a deflection plate connected to the mounting bracket. The deflection plate, disposed at a vertical position lower than the tilt axis, extends between the transom and the drive unit mounted to the stern bracket mounted to the transom. A left deflection wing, connected to at least one of the deflection plate and the mounting bracket, extends downward and laterally outward therefrom. A right deflection wing, connected to at least one of the deflection plate and the mounting bracket, extends downward and laterally outward therefrom. A watercraft is also disclosed.

Abstract: A sidewall planing boat includes: a body; sub-bodies; and a power device; wherein the two sub-bodies are mounted on a front portion of the body and are symmetrically provided at two sides of the body; bottom surfaces of the sub-bodies are lower than a bottom surface of the body; wherein rigid sidewalls are symmetrically mounted on side surfaces of the body, rigid sub-sidewalls are symmetrically mounted on side surfaces of the sub-body; portions of the sidewalls and the sub-sidewalls which extend to a bottom of the sidewall planing boat are inserted into water for forming three lifting areas with front openings with the bottom; wherein the power device is mounted on the body and/or the sub-bodies. With the foregoing structure, water resistance of the sidewall planing boat is decreased and a sailing speed in increased.

Abstract: Hydrodynamic duct mounted at the bow of a vessel, comprising a horizontal wall portion (1) and two lateral wall portions (2,3), whereby the flow through the duct acquires substantially different characteristics from the flow outside it and thereby wave making and frictional resistances are reduced and the fuel conventionally required for the propulsion of the vessel is reduced accordingly. The duct is arranged with the Center of Low Pressure (1c) corresponding to a zero angle of attack onto the horizontal wall portion (1) being located in the region of generation of the first bow wave and with the Centers of Low Pressure (2c,3c) of the lateral wall portions (2,3) in the region of connection thereof with the horizontal wall portion (1) being located in a selected position between the Center of Low Pressure (1c) and up to or slightly forwardly the leading edge (1a) of the horizontal wall portion (1).

Abstract: A watercraft having a hull, a mast with sail, an aft rudder and a hydrofoil projecting below the bottom of the hull. The hydrofoil is pivotly connected to the hull enabling the hydrofoil to pitch on a pivot axis which is essentially perpendicular to the longitudinal axis of the hull. The hydrofoils have a vertical part which produces lateral forces to accelerate the boat in turns and resist lateral forces from the sail, and a vertical portion which curves into the horizontal portion which produces vertical lift. The angle of incidence of the hydrofoil is controlled by a sensor arm carrying a trailing sensor.

Abstract: A catamaran (10) has two spaced demihulls (12) which are connected by an upper superstructure above the waterline. The catamaran (10) includes a main hydrofoil (26) extending between the demihulls at keel level slightly forward of the longitudinal center of gravity LCG (22) of the catamaran. Each demihull (12) defines an aft swept step formation (28) located slightly forward of the LCG (22) and extending transversely relative to a longitudinal center line CL defined between the demihulls. Each step formation (28) defines a step extending along a straight line and having a height dimension which tapers from an inner position at the keel (18) of the hull towards an outer position at the chine (20) of the hull. Each demihull defines a planing region immediately in front of the step formation (28), which has a concave hydrodynamic profile configured to generate lift on a wetted area of the hull.

Abstract: A hull for a planing type watercraft has a front lift surface, a high lift surface, and a back planing surface. The high lift surface is adjacent a rockered keel area and between the front lift surface and the back planing surface. The center of dynamic lift on the high lift surface is at or in front of a point which is 15% of the hull length behind a total center of gravity of the hull under loading. At least the back one third of the high lift surface is cambered, and a beam of the high lift surface is greater than two thirds of the maximum width of the hull. The average camber of the front lift surface, the high lift surface, and the back planing surface together is less than or equal to zero.

Abstract: A sea-bed anchor of the plug-and-socket type, in which the depth of the socket (2) needed to keep the plug in the socket against tidal force is reduced by the downwards force from a hydrofoil (5). The same force is used to lock the plug and socket positively together. The effective area of hydrofoils (5) can be increased when the tide is flowing and reduced when it is not. Downwards force from the hydrofoils is also used to enable submersible vessels to drill sockets in rock or to embed suction anchors in sediment.

Abstract: In one example, a watercraft is provided that includes a body. The body has a hull and a ramp that slopes downwardly toward a back of the hull. Additionally, a reverse chine geometry is incorporated in a portion of the bottom of the hull. Finally, one or more projections extend downward from the bottom of the hull.

Abstract: A sailboard hull has at least one pair of winglets or foils beneath the top of the board. Each winglet or foil has above it a slot and allows dynamic lift from both the top and bottom surface of the winglet and reduction of drag when the board is traveling at a transition speed between displacement mode and planing mode. At high planing speed it does not normally have lift from the top surface of the winglet. There may be multiple pairs of winglets or foils. Back slots may be provided at the rear of the sailboard hull providing a higher ratio of winglet width to maximum hull width. A top slot may cover at least half the winglet area, and a winglet may have a camber/slope step on the planing surface.

Abstract: A foil structure for providing buoyancy and lift to a floating device is provided. The foil structure comprises an elongated left hand side floating device section and an elongated right hand side floating device section. The left hand side floating device section and the right hand side floating device section are placed at a predetermined distance to a longitudinal axis of the floating device and oriented substantially parallel thereto. A left hand side foil and a right hand side foil protrudes from the left hand side floating device section and the right hand side floating device section, respectively, towards a vertical plane through the longitudinal axis and is oriented at an acute angle to a horizontal plane. A leading edge of each foil intersects the respective floating device section in proximity to a bow portion thereof. Each foil extends along the respective floating device section and terminates in proximity to a stern portion thereof.

Abstract: A turbine integrated within a hydrofoil extracts energy from a free-flowing motive fluid. In the preferred embodiment, the turbine is of the crossflow variety with runner blades coaxial to the width of the hydrofoil. The foremost edge of the hydrofoil comprises a slot covered by a continuously adjustable gate for controlling the overall drag imposed by the turbine. The hydrofoil mounts to a sailing vessel by means of a gimbal on a structure affixed to the hull, enabling the turbine to optimally respond to changes in direction of the free-flowing motive fluid and facilitating guidance and stability of the vessel.

Abstract: A multi-modal watercraft including a hull including a missing portion. A floor completes at least part of the missing portion of the hull and forms the floor of a hold. The floor can be raised and lowered from the water level and also is detachable from the hull.

Abstract: A paint drying booth includes a plurality of walls, a ceiling, and an access door for egress and ingress. A turbine generates heated compressed air which is delivered to the interior of the booth via a duct system. The duct is in fluid communication with an air knife having a slit which delivers a stream or sheet of air into the interior of the booth. More than one air knife can be provided, and the orientation of the plurality of air knives are coordinated to provide a flow of heated turbulent air within the booth to accelerate the drying of painted items within the booth. The turbine comprises a multi-stage compressor including a plurality of rotors and stators for compressing air passing therethrough. Optionally a pneumatic spray gun can be provided for painting the items within the booth as well.

Abstract: To a watercraft which includes a main hull and at least one outrigger which is fastened in a height-adjustable manner to the main hull.

Abstract: A marine vessel comprising: a command module; first and second buoyant tubular foils; and first and second struts for connecting the first and second buoyant tubular foils to the command module, respectively; wherein the first and second buoyant tubular foils provide substantially all of the buoyancy required for the marine vessel; and wherein the marine vessel further comprises first and second engines enclosed within the first and second buoyant tubular foils, respectively, and first and second propulsion units connected to the first and second engines, respectively, for moving the marine vessel through the water.

Abstract: A hydrofoil boat stabilizer having a cross-sectional area with the configuration of a true hydrofoil is provided. The hydrofoil includes a slip-on yoke designed to compressively fit on a cavitation plate of a boat motor lower drive unit. The wings of the hydrofoil include at least one angle of attack, and preferably, a plurality of angles of attack. The hydrofoil is shaped to reduced drag and minimize cavitation. A low-drag surface is included on at least a portion of the outer surface of the hydrofoil.

Abstract: A boat stabilizer that is attachable to the anti-cavitation plate or other structure of the lower drive unit of a boat motor without permanently modifying the structure of the anti-cavitation plate or other structure is provided. The shape and size of the boat stabilizer causes the stabilizer to effectively harness and control the thrust energy generated by the propeller resulting in improved thrust and fuel efficiency. Due to various features, the drag associated with the boat stabilizer is kept to a minimum. Finally, decals and other decorative elements are integrally embedded into the top surface of the inventive boat stabilizer using in-mold decoration (“IMD”) technology which makes the elements resistant to ultra-violet light, virtually indestructible and highly appealing. A boat motor, a method of attaching a boat stabilizer to a boat motor and a method of molding a boat stabilizer having at least one decorative element integrally embedded in the top surface thereof are also provided.

Abstract: A watercraft device according to the invention includes a central body and two lateral hulls, each having a shape optimized to reduce resistance to the advance motion and connected to the central body through at least one connecting arm, causing the central body to be in raised position with respect to the lateral hulls. The connecting arms have a given angle from the horizontal plan of the device, and the lateral hulls and the central body are oriented with longitudinal axes, or axes in the bow-stern direction, essentially parallel to each other. The central body connecting the lateral hulls is shaped like wing, which helps in sustaining the weight of the vehicle at high speed and exploits ground effect to increase aerodynamic efficiency. In addition, each of the lateral hulls has one or more mobile and/or fixed hydrofoil elements that extend below the corresponding lateral hull.

Abstract: A towable buoy having a tow point for connection to a tow cable of a vessel, wherein the position of the tow point is translationally moveable with respect to the remainder of the buoy. Also, a method of operating the towable buoy.

Abstract: A sea bed anchor of the plug-and-socket type, in which the depth of the socket (2) needed to keep the plug in the socket against tidal force is reduced by downwards force from a hydrofoil (5). The same force is used to lock the plug and socket positively together. The effective area of hydrofoils (5) can be increased when the tide is flowing, and reduced when it is not. Downwards force from hydrofoils is also used to enable submersible vessels to drill sockets in rock or to embed suction anchors in sediment.

Abstract: The invention relates to a spar based vessel for accessing offshore installations and vessels, including wind farm turbines, in which the centre of gravity of the vessel is positioned below the centre of buoyancy, which is positioned below the operational waterline, the operational waterline occurs at low cross-sectional area vertical struts, and the vertical struts support a topside structure for passengers. Active ballast control system and location of the propulsive elements permits the vessel to travel in spar orientation by positioning the vector of propulsion to lie in the same horizontal plane as the transverse centre of drag of the vessel. A docking system permits safe connection of the vessel to offshore installations, including wind turbines of generic design.

Abstract: There is provided a boat (200) including a hull (20), and two engines (30, 50) couplable to rotationally drive mutually spaced separate corresponding propeller assemblies for providing thrusts. Directions of the thrusts are angularly adjustable (?1, ?2) relative to the hull (20). A control unit (70) receives first and second user commands (S1, S2) and sends corresponding signals for controlling powers (P1, P2) coupled from the engines (30, 50) to their propeller assemblies. The control unit (70) determines a difference in power (?P) to be coupled to the propeller assemblies as a function of the first and second user commands (S1, S2). The control unit (70) controls coupling of power (P1, P2) to the propeller assemblies so that the propeller assemblies develop a difference in thrust which is a function of the difference in power (?P).

Abstract: A marine vehicle with at least one hydrofoil at the lower hull of such marine vehicle, and at least one drive element for retracting a pair of hydrofoils mounted side-by-side on both sides of the symmetry axis of the hull of the marine vehicle. When hydrofoils are in the retracted position, the marine vehicle is converted to a conventional marine vehicle.

Abstract: A motorized airplane includes a landing gear with at least two legs capable of retracting into the fuselage via hatches. A pair of hydrofoils is fitted to the base of the fuselage in conformance with the ailerons used for lift and hydrodynamic stability, directed towards the base like a reverse V shape. The legs of the landing gear are each articulated around the pivot axes, fitted onto the hydrofoils. The landing gear is dual-function, using wheels or skis suspended on legs. Applications: airplane for landing on water, ground and snow.

Abstract: A catamaran (10) has two spaced demihulls (12) which are connected by an upper superstructure above the waterline. The catamaran (10) includes a main hydrofoil (26) extending between the demihulls at keel level slightly forward of the longitudinal centre of gravity LCG (22) of the catamaran. Each demihull (12) defines an aft swept step formation (28) located slightly forward of the LCG (22) and extending transversely relative to a longitudinal centre line CL defined between the demihulls. Each step formation (28) defines a step extending along a straight line and having a height dimension which tapers from an inner position at the keel (18) of the hull towards an outer position at the chine (20) of the hull. Each demihull defines a planing region immediately in front of the step formation (28), which has a concave hydrodynamic profile configured to generate lift on a wetted area of the hull.

Abstract: A boat propulsion engine (1) comprises a main body (4) that extends substantially vertically in relation to a hull (Si), a lift generator (20) disposed in a rear portion of the main body (4), and supporting bodies (24) that support the lift generator (20) on the main body (4). The lift generator (20) has a surface (21g, 21h) that extends transversely relative to the main body (4) and that is located behind at least the main body (4). The supporting bodies (24) extend backward from the main body (4) to the lift generator (20) in a single vertical direction relative to a surface (21g, 21h) of the lift generator (20).

Abstract: The disclosure relates to marine craft which are capable of operating in the hydrofoil mode, many with extensible and retractable hydrofoil posts. Specific embodiments of large commercial hydrofoil craft are described, including those with structure which is the water during hydrofoil travel mode and which can be retracted to partly fit within recesses in the hull during other operating modes. Other craft, including those with hybrid electric drive, are disclosed having un-cooled reciprocating internal combustion engines. A number of arrangements for pistons and cylinders of unconventional configuration are described. These included are toroidal combustion or working chambers, some with fluid flow through the core of the toroid, pistons reciprocating between pairs of working chambers, tensile links between piston and crankshaft, energy absorbing piston-crank links, crankshafts supported on gas bearings. In some embodiments pistons mare rotate while reciprocating.

Abstract: A towable water sports device having a hydrofoil assembly including a strut, fuselage and front and rear blades carried by the fuselage wherein said parts are extruded aluminum or aluminum alloy.

Abstract: The present invention is a water wings device used in combination with a watercraft that includes a plurality of water wings attached to the sides of the watercraft with attachment arms and directing fins that are placed into the water that the watercraft is traveling in. There is also an embodiment of the water wings device that includes a boat tail with a tapering protrusion that is placed into the water the watercraft is traveling in. Another embodiment is the water tail device that includes a plurality of water tails that attach to the rear of portion of a watercraft used in conjunction with water wings on the side of the watercraft that are all placed into the water the watercraft is traveling in.

Abstract: A hull (1) for a marine vessel (10) comprising an elongate body (2) that tapers outwardly from a foremost location, the bow (3), and tapers inwardly toward the aft (4) such that the aft (4) of the body (2) is significantly reduced in profile with respect to a point in the hull at which the inward taper commences.

Abstract: This invention relates to water sports equipment (10) for supporting a standing rider whilst the rider and the equipment are towed through the water, the equipment comprising: an elongate board (14) having an upper surface (16) carrying first (31, 33) and second (32, 34) foot securing means, said foot securing means being configured to be engaged by a respective foot of the rider so that the rider can stand on the board (14) with their body facing in a direction generally perpendicular to a direction in which the rider and equipment are towed through the water in use; a hydrofoil (11) having a longitudinal axis, said hydrofoil (11) being configured to impart lift to the board (14) when the rider and board are towed through the water; and means (12, 13) for affixing said hydrofoil (11) to said board (14) so that the hydrofoil is spaced from a lower surface (15) of the board and orientated such that said hydrofoil longitudinal axis is substantially transverse to the direction in which the rider and equipment ar

Abstract: A water craft including a hull having a main longitudinal axis defining a direction of travel of the craft, a plurality of discs mounted at respective opposed sides of the main longitudinal axis to and below the hull and in combination having sufficient buoyancy to support the hull above the water, each disc comprising an essentially circular convex skimming surface adapted to skim upon the water as the craft moves at low speed, wherein the discs are mounted to the hull such that the skimming surface of each disc faces downwardly with respect to the longitudinal central axis of the hull, and adapted for movement between a low speed orientation in which the discs present a portion of the circular convex skimming surface to the water surface and a high speed orientation in which the discs present a portion of the edge of the disc to the water.

Abstract: The present invention relates to a water craft (10) having two spaced hulls (18, 20) and a tunnel (22) defined therebetween. The water craft (10) is provided with a hydrofoil section (38) extending between the hulls (18, 20) and across the tunnel (22). The tunnel facing side of each hull (18, 20) is provided with a recess (50) which extends from a position rearward of the bow (24) of the water craft (10) to the stern (26) of the water craft (10). Each recess (50) includes a side wall (52) which extends upwardly from the keel line of each hull (18, 20) and an upper wall (56) which is inclined downwardly in the direction of the stern (26). Each recess (50) is further provided at a rearward portion thereof with a skirt (58) positioned inboard of the side wall (52) so as to define an open sided channel between the skirt (58), sidewall (52) and downwardly inclined upper wall (56) of the recess (50).

Abstract: In a boat-propelling machine for attachment to a boat hull (200), an outer wall unit (4) is fixedly provided on a body of the machine for covering part of a cylindrical structural body (60) that is formed of metal alloy and positioned so as to be at least above a draft line during planning of the boat, and a lift force generation device (20) is provided on the outer vertical wall unit.

Abstract: A vessel (10) for traveling on water comprises a hull (20) and a keel (30) comprising a member (34) depending from the hull, the member (34) comprising two limbs (44) each depending from a respective lateral side of the hull (20), the two limbs (44) defining at least in part an enclosed flow path extending in a bow to stern direction, the enclosed flow path being configured to allow water incident on the vessel to flow over inner and outer surfaces of the limbs (44a, 44b). The limbs (44) each have a zero-lift surface which is angled to generate in use a component of hydrodynamic force directed away from the enclosed flow path when there is a net flow of water along the enclosed flow path.

Abstract: A foil guard for sporting devices having hydrofoils covers the exposed edges of the foils and thereby prevents damage to persons or property from accidental contact with the foils. The guard may include cords or elastics to secure the guard to the foils, and may float in water to prevent loss of the guard.

Abstract: A self-propelled hydrofoil device that includes a front foil, a rear foil, a user platform, a steering shaft and a frame that couples these components. The steering shaft preferably has a top section and a lower section, the top section being substantially rigid and the lower section being flexible relative to the top section. The top and lower sections may be formed of different materials or may be formed of the same material, integrally or non-integrally. The top and lower sections are preferably offset by an angle, ?, to achieve more ready bending of the lower section.

Abstract: A method and a device for suppression of cavitation and thus for reducing resistance to movement of a streamlined body in a flow of liquid based on the principle that development of cavitation bubbles in the area of separation of the flow that is accompanied by the development of turbulence is prevented by injecting a gaseous medium into the aforementioned area for separating the flow of liquid from the surface of the streamlined body. The device of the invention can be realized in the form of various specific embodiments with supply of gas under pressure to the cavitation-development area through a plurality of perforations and transverse slits.

Abstract: A self-propelled hydrofoil device having front and rear foils, a support structure and a steering mechanism. The hydrofoil device is preferably configured such that a user can change the angle of attack of the drive foil and/or the height of the hydrofoil device in the water by placing the handle bar to a corresponding position. The steering mechanism is movably coupled to the user platform in a manner that provides a user with sufficient leverage to move the handle bar. A flexible steering-shaft joining member and dihedral foil configurations, among other features, are disclosed.

Abstract: An apparatus for underwater propulsion. The apparatus may include a hydrofoil, a buoyancy compensator connected to the hydrofoil, a tank containing air, and a controller regulating the passage of air from the tank into the buoyancy compensator. The controller may also regulate the escape of air from the buoyancy compensator. By positioning the hydrofoil underwater and alternating between positive and negative angles of attack, a diver may generate forward propulsion by manipulating the controller to correspondingly alternate the buoyant force produced by the buoyancy compensator between levels below and above neutral buoyancy.

Abstract: A ski structure for use with a boat hull to support the hull above the water when the boat is underway, the ski structure comprising an air tight housing in the form of an inverted U-shaped shell and a floor which forms a main ski surface and which extends between opposite sides of the U-shaped shell. The ski structure also includes a pair of assist skies or glides positioned lower than the main ski surface which extend substantially the length of the shell and which are adapted to plane on the surface of the water.

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: An open sea hydrofoil craft comprising a hull (A) with lateral vertically oriented blades (B1,B2) extending longitudinally along the two sides thereof, the interior surfaces of blades (B1,B2) lying one opposite the other being planar and defining in between them an initially convergent and subsequently divergent water flow channel, whilst their exterior surfaces have a curved configuration that dynamically changes in three dimensions (x, y, z) with variable angular parameter (?1) formed by the bottom of blades (B1,B2) with (y) axis, (?2) formed by the curved section of the exterior surfaces or blades (B1,B2) with (z) axis and (?1,?2) formed by an arcuate lateral edge (20) of blades (B1,B2) with (x) axis. Lift producing foils (C1,C2,C3) with a hydrofoil section are provided within the channel formed in between blades (B1,B2), these lift producing foils (C1,C2,C3) being connected to the hull (A) by means of supporting plates (C1?, C2?, C3?) respectively.