A steering apparatus of a hydrofoil includes first to fourth propulsion portions, a central connecting portion, a left hydrofoil, and a right hydrofoil. Among the first to fourth propulsion portions, the first propulsion portion 41 and the third propulsion portion are disposed on the left side, and the second propulsion portion and the fourth propulsion portion are disposed on the right side. The central connecting portion connects the first to fourth propulsion portions with each other via a first fixing portion and a second fixing portion. A left hydrofoil and a right hydrofoil are respectively attached to outer sides of the central connecting portion via the first fixing portion and the second fixing portion.

A fully electric hydrofoil boat comprises an elongated hull, a front canard hydrofoil supported by a front support system configured to raise or lower thereof, and a pair of independently-controlled port and starboard rear stowable hydrofoils supported by their respective rear support systems, configured to raise or lower the rear hydrofoils to a selected depth or tilt them out of the water when docking or transporting the boat on a trailer. The hull has a cut-out section in the front portion sized to fit the front canard hydrofoil out of the water if desired. The boat may operate energy-efficiently in a hydrofoil flight mode at high speeds or in a displacement mode at slow speeds when the hydrofoils are in their raised positions.

A hydrofoil vehicle comprises a frame and at least one foil. The vehicle comprises a moveable control surface configured to control a pitch of the vehicle, in use. A locking mechanism is provided for restricting movement of the control surface when the vehicle is not foiling, for example during launching. In examples, the locking mechanism activates automatically when the hydrofoil vehicle is not foiling. In examples, the vehicle is human powered.

A watercraft fin that dynamically keep a neutral alignment within the range of angles a user chooses to have and/or change in respond to the flow conditions so reducing drag. Hence, this invention is such to enable a fin to rotate within a range of angles via a rotary bearing and bearing housing which are to receive a fin having a journal base. The housing is to be fitted to a watercraft such as a surfboard, the housing having a changeable circular keyway to loosely receive a shear key at the underside of the journal base as to allow free circular motion of the shear key and correspondingly the journal base and the fin within the limits of the selected circular length of the keyway. In one form the fin is fitted with a root portion adapted to be inserted into a receiving portion extending radially in the journal base and trapped within the bore of the bearing.

A fully electric hydrofoil boat comprises an elongated hull, a front canard hydrofoil supported by a front support system configured to raise or lower thereof, and a pair of independently-controlled port and starboard rear stowable hydrofoils supported by their respective first and second rear support systems, in turn configured to raise or lower the first and second rear hydrofoils to a selected depth or tilt them out of the water when docking or transporting the boat on a trailer. The hull has a cut-out section in the front portion sized to fit the front canard hydrofoil to be out of the water if desired. The boat may operate energy-efficiently in a hydrofoil flight mode at high speeds or in a displacement mode at slow speeds when the hydrofoils are in their raised positions.

A hydrofoil boat incorporates an elongated hull with front and rear portions and deployable hydrofoils for enhanced performance and maneuverability. A front canard hydrofoil is mounted on a front support system positioned at the hull's front portion, configured to be moved between a stowed position and an operating position. The rear portion of the elongated hull supports a pair of rear hydrofoils, each mounted on respective rear support systems. Each rear hydrofoil integrates a motor-driven propeller, with the rear support systems configured both to raise or lower the hydrofoils between stowed and operating positions and to rotate the propellers about vertical axes to facilitate directional steering. The arrangement allows selective deployment of the front and rear hydrofoils above or below the water line, enabling efficient lift, reduced drag, and improved control. The system further enables the retrieval of one or all the hydrofoils above the water line when not in use.

Safety strut assembly (9) for a hydrofoil craft (1) comprising a strut (12), which is attached to the hull (10) of the craft by means of a transverse oriented strut axle (40) for pivotal movement with respect to the hull, the assembly further comprising: a control rod (33) passing down through the strut (12); a linear actuator assembly (28); a hydrofoil (13) pivotally mounted to the bottom portion of the strut (12) about a transverse oriented foil axle (35); first linkage means (34) connecting the hydrofoil (13) to the control rod (33); wherein the first linkage means (34) comprises a first drive ring (48) mounted around the foil axle (35), wherein the first drive ring is provided with one first ring cam element (45), and wherein the foil axle (35) is provided with one foil axle cam element (46).

A hydrofoil apparatus includes a pair of hydrofoil modules each including a clamp bracket, a swivel bracket, a wing including a hydrofoil, and a rotation actuator. In a reference state in which angles of attack of the hydrofoils of the pair of hydrofoil modules are the same as each other, a first rotation shaft is located forward of a center of an area of the hydrofoil.

A sponson device attachable to a watercraft body of a jet propelled watercraft includes a bow sponson located forward of a center of gravity of the jet propelled watercraft. The bow sponson protrudes from the watercraft body in a right-and-left direction, and is movable to a first position and a second position to adjust a trim of the watercraft body during turning of the jet propelled watercraft.

A hydrofoil system for a hydrofoil equipped watercraft with cooperating fuselage portion that have tapered sections. The tapered sections are configured to form an overlapping stacked wedge within an inner passageway of a collar so that the collar frictionally engages the stacked tapered sections when the first fuselage portion and the second fuselage portion are drawn together longitudinally.