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 hydrofoil system provides lift to a motor-powered displacement hull without raising the hull out of the water. The hydrofoil system includes a pair of laterally opposed forward hydrofoil wings positioned respectively on the first pontoon and second pontoon forward a center of gravity of the hull. The forward hydrofoil wings extend laterally inboard and downwards towards each other. The hydrofoil system also includes a pair of laterally opposed aft hydrofoil wings positioned near the stern of the hull on the first pontoon and second pontoon respectively. The aft hydrofoil wings extend laterally inboard towards each other and have an upper surface with convex curvature that extends from the respective first pontoon or second pontoon to an inboard terminal end thereof.

A steering system for a hydrofoil watercraft, wherein a user may ride in a seated, prone, kneeling, or standing position while steering the watercraft without the use of his or her bodyweight. Vertical elevation, left and right roll, and longitudinal direction control of the watercraft is accomplished via steering, resulting in movement of the control surfaces (fins) on the hydrofoil, thus eliminating the need for weight shifting on the flotation device. An electronic remote and/or mounted joystick steering system can be operated either electronically or through direct mechanical linkage to control the direction of the watercraft. The steering system can include an unmanned remote controlled drone hydrofoil watercraft that can be operated remotely.

A system for retracting a foil of a watercraft in the event of an impact has a strut extending from a watercraft, the strut has a pivot at one end that connects the strut to the watercraft and allows the strut to articulate around the pivot, a foil attached at a second end of the strut, wherein the foil has sufficient surface area configured to generate positive lift when the watercraft is traveling over water; and a retraction system including a mechanical fuse connected to the strut, the mechanical fuse holds the strut stationary and is subject to forces from the strut when the strut travels through water, the retraction system allows retraction of the strut around the pivot when the strut experiences a force greater than a predetermined limit, and the foil is configured to articulate on the strut to maintain positive lift orientation as the strut is retracting.

A system for retracting a foil of a watercraft in the event of an impact has a strut extending from a watercraft, the strut has a pivot at one end that connects the strut to the watercraft and allows the strut to articulate around the pivot, a foil attached at a second end of the strut, wherein the foil has sufficient surface area configured to generate positive lift when the watercraft is traveling over water; and a retraction system including a mechanical fuse connected to the strut, the mechanical fuse holds the strut stationary and is subject to forces from the strut when the strut travels through water, the retraction system allows retraction of the strut around the pivot when the strut experiences a force greater than a predetermined limit, and the foil is configured to articulate on the strut to maintain positive lift orientation as the strut is retracting.

A method and a controller unit for controlling motion of a watercraft with a hydrofoil) obtains information indicating shape of water surface in front of the hydrofoil. The controller unit further predicts wave acceleration of the watercraft using a neural network. Furthermore, the controller unit determines a target route and corresponding total acceleration of the watercraft under a set of constraints. The total acceleration is minimized when the watercraft travels according to the target route. The set of constraints includes: a first constraint that the hydrofoil stays within an interval relative to the water surface, and a second constraint relating to magnitude of acceleration derived from maximum AoA and the predicted wave acceleration. The controller unit calculates an AoA for the target route. Next, the controller unit sends a signal for adjusting the hydrofoil according to the AoA.

A foil displacement system includes one or more foils that can be deployed and stowed. When deployed, each foil can exert downforce or uplift depending on its orientation. For example, each foil may be positioned to have an angle of attack that creates a downward force effectively transmitted to the hull to pull the hull deeper within the water to, for example, create a larger wake. Use of the foil displacement system can enhance or replace the use of a ballast tank system, can be integrated into a new boat or retrofitted to existing boats, can be electronically or manually positioned, can enhance activities such as wake surfing, wake boarding, water skiing or other similar or related water sports.

Systems, apparatus, and methods for hydrofoil assemblies with planing blades that may be adjusted, and securely maintained in varying tilts with respect to a support member, using a curved indexing system with a curved ridge and a counterpart groove that utilize interacting position retaining elements to retain a desired tilt in different adjustable positions. In one illustrative system, a planing blade may have a convexly curved ridge disposed on a surface thereof with a series of transverse grooves disposed in the curved ridge. A support member may have a counterpart concavely curved receiver with a series of counterpart transverse grooves formed therein. When a user places the planing blade in position with the convex ridge contacting the concave receiver, the blade may be tilted to a desired position. The counterpart transverse grooves interconnect to provide an indexed positive interlock, securely maintaining the blade in the desired position.

An example wing-in-ground effect vehicle includes (i) a main wing having main wing control surfaces; (ii) a tail having tail control surfaces; (iii) a blown-wing propulsion system arranged along the main wing or the tail; (iv) a retractable hydrofoil configured to operate in: (a) an extended configuration in which the retractable hydrofoil extends below a hull of the vehicle for submersion below a water surface and (b) a retracted configuration in which the retractable hydrofoil is retracted at least partially into the hull of the vehicle; and (v) a control system configured to maneuver the vehicle by (i) causing a change in orientation of the retractable hydrofoil when the retractable hydrofoil is operating in the extended configuration, and (ii) causing a change in orientation of the main wing control surfaces and tail control surfaces when the retractable hydrofoil is operating in the retracted configuration.

A watercraft comprising: a chassis; a drive means; a hydrofoil; and a drive transfer arm, wherein the drive means is operatively connected to a first end of the drive transfer arm, and the hydrofoil is pivotably connected to a second end of the drive transfer arm, the watercraft configured such that operation of the drive means causes the hydrofoil to oscillate, to provide thrust.