The present disclosure provides generally for a hydrofoil system that may allow a surfboard to glide above the water surface. According to the present disclosure, a rider may be able to manipulate a hydrofoil device attached to a surfboard with limited training and athletic ability. The present disclosure provides for a hydrofoil system that may allow riders to use a light leaning motion to adjust the angle of a front wing to create forward thrust to produce a flow for creating lift. In some aspects, the front wing may tilt to reduce downward drag force in a lifting phase while locking into place during a glide to provide a sustained lift of the surfboard out of the water.

A boat includes at least three trim devices positioned aft of the boat's transom. To improve the boat's ability to get on place, each trim device is initially positioned to a deployed position. The speed of the boat is then determined as the boat gains speed. When the speed of the boat exceeds a first predetermined threshold, the first trim device is moved from the deployed position to a non-deployed position. When the speed of the boat exceeds a second predetermined threshold, the second trim device is moved from the deployed position to a non-deployed position. When the speed of the boat exceeds a third predetermined threshold, the third trim device is moved from the deployed position to a non-deployed position. At least one of the first, second, and third predetermined thresholds is different from the other two of the first, second, and third predetermined thresholds.

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.

A powerboat comprising a hull, a plurality of dynamically adjustable hydrofoils positioned below the waterline towards the rear of the hull, and a control system, wherein the cross sectional area of the hull below the waterline decreases towards the rear of the hull, and the control system is configured to adjust the hydrofoils in operation of the powerboat to control the running trim of the powerboat. The powerboat can operate efficiently at over a wide range of Froude numbers, in particular both low (displacement mode) speeds and high (planing mode) speeds.

A boat includes at least three trim devices positioned aft of the boat's transom. To improve the boat's ability to get on place, each trim device is initially positioned to a deployed position. The speed of the boat is then determined as the boat gains speed. When the speed of the boat exceeds a first predetermined threshold, the first trim device is moved from the deployed position to a non-deployed position. When the speed of the boat exceeds a second predetermined threshold, the second trim device is moved from the deployed position to a non-deployed position. When the speed of the boat exceeds a third predetermined threshold, the third trim device is moved from the deployed position to a non-deployed position. At least one of the first, second, and third predetermined thresholds is different from the other two of the first, second, and third predetermined thresholds.

A watercraft structure (100) comprises a hull (110) and a lifting surface (120) connected to the hull (110) and immersed at least partially in water, said lifting surface (120) adapted to generate a lift force suitable for supporting the hull (110), said lifting surface (120) comprising a movable portion (125) arranged to rotate relatively to the watercraft (100), between a position of higher lift and a position of lower lift. The watercraft structure (100) also comprises an actuating mechanism (130) arranged to actuate the movable portion (125) between the above described positions. The actuating mechanism (130) comprises a containing volume comprising a first chamber (141) at a pressure P.sub.a and a second chamber (142) at a pressure P.sub.b divided by a septum (145), said septum (145) having a first face (145a) having surface S.sub.a and oriented towards the first chamber (141) and a second face (145b) having surface S.sub.b and oriented towards the second chamber (142). The actuating mechanism (130) also comprises a reference channel (152) hydraulically connected to the second chamber (142), said reference channel (152) being in communication with the external environment by a reference opening (152) that, in use, is constantly below the level of the water and is oriented in the motion direction. The actuating mechanism (130) comprises then a compensation channel (151) hydraulically connected to the first chamber (141), said compensation channel (151) being in communication with the external environment by at least one respective compensation opening (151) located at a greater height respect to the reference opening (152), said or each compensation opening (151) being oriented in the motion direction.

Wakeboat hull control systems and methods are provided to permit the accurate reproduction of a wake behind a wakeboat. The onboard wake control system receives data from a draft measuring system. Incorporation of the data from the draft measuring system permits accurate reproduction of a wake behind the wakeboat after a change in an onboard variable such as the number, weight or position of passengers, the weight or position of cargo and the position of trim tabs or amount/location of ballast.

A hydrofoil may include a starboard support structure and a port support structure. Each structure may be hollow and extend longitudinally in a fore-aft direction and being parallel to one another. The hydrofoil may include an anhedral wing having ends at either side of the wing. The ends may be connected to the starboard and port support structures. The hydrofoil may include a starboard electric propulsor mounted to the starboard support structure and a port electric propulsor mounted to the port support structure. The hydrofoil may also optionally include a front wing having ends at either side of the front wing. The ends of the front may be connected to the starboard and port support structures.

A craft comprises at least one hull; at least one wing configured to generate upwards aero lift as air flows past the at least one wing to facilitate wing-borne flight of the craft; a front hydrofoil connected to the at least one hull via a front hydrofoil strut and configured to generate upward hydrofoil lift as water flows past the front hydrofoil to facilitate hydrofoil-borne movement of the craft through the water; a rear hydrofoil connected to the at least one hull via a rear hydrofoil strut and configured to generate upward hydrofoil lift as water flows past the rear hydrofoil to facilitate hydrofoil-borne movement of the craft through the water; and a control system. While the craft is hydrofoil-borne, the control system is configured to facilitate transition of the craft from hydrofoil-borne operation to wing-borne operation via a process comprising: while the upwards aero lift generated by the at least one wing is below a threshold lift, controlling one or both of the front hydrofoil and the rear hydrofoil to generate a downward hydrofoil lift that causes the front hydrofoil and the rear hydrofoil to remain at least partially submerged in the water; and after the upwards aero lift generated by the at least one wing has increased above the threshold lift, transitioning the craft from hydrofoil-borne operation to wing-borne operation at least in part by controlling one or both of the front hydrofoil and the rear hydrofoil to switch from (a) generating the downward hydrofoil lift to (b) generating an upward hydrofoil lift that pushes the craft up and out of the water.

The invention relates to a hydrofoil for a watercraft including a fuselage and two wings arranged on either side of the fuselage and designed to provide hydrodynamic lift to the hydrofoil when it is moving through the water. According to the invention, the two wings are rotatable relative to the fuselage between a deployed position when the hydrofoil is stationary, and a retracted position towards a rear part of the fuselage by the water pressure exerted on the wings when the hydrofoil is moving through the water.