A stabilized a hydrofoil water craft comprising: a water-craft base member, a hydrofoil mast having proximal and distal portions; said proximal portion mechanically connected to said bottom side of said water-craft base member, a fuselage mechanically connected to said distal portion of said at least one hydrofoil mast, a rudder configured for controlling a yaw angle of said water craft, an elevator rotatable around an axis lying in a plane parallel to water-craft base member and a stabilization arrangement further comprising at least one sensor configured for detecting a 3D orientation of said water-craft base member, an estimator configured for estimating the 3D orientation, actuators for manipulating the rudder and elevator and a controller for analyzing the estimated 3D orientation and controlling the actuators. In response to a disturb roll inclination of the water craft, the controller generates a command to a rudder actuator to compensate the detected inclination.

Various embodiments are disclosed for a stepped cambered planing hull for a boat including a swept back cambered planing surface having a non-linear distribution of camber. The non-linear distribution of camber along the swept back cambered planing surface may enable stepped cambered planing hulls having high deadrise (i.e., greater than 15 degrees). The stepped cambered planing hull may include a shaped hydrofoil that generates further hydrodynamic lift by piercing the free surface wake produced by the swept back cambered planing surface. The stepped cambered planing hull may have external bottom surfaces adapted at the after-body and transom to accommodate a distinctive profile of the free surface wake produced by the swept back cambered planing surface. The stepped cambered planing hull may include an adjustable interceptor blade to regulate hydrodynamic lift at low speeds or to ensure an optimal dynamic trim angle in a wide range of speeds.

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.

The present disclosure generally pertains to a lateral displacement surf system and methods of laterally displacing a watercraft to generate wake. The lateral displacement system includes at least one pair of foils configured to be extended from a hull on a first side of the watercraft at a level of approximately the waterline. Upon forward movement of the watercraft with extended foils, the watercraft is rotated about its vertical axis toward the first side and generates waves sufficient for the conduction watersport activities on a second side of the watercraft. In some instances, foils are built into the hull and extended from this position, while in other instances the foils are attached to the hull using attachment structures. Rotation of the foils about an axis of rotation approximately perpendicular to a longitudinal axis of the watercraft alters the angle of attack of the foils relative to the waterline.

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.

The present disclosure generally pertains to a lateral displacement surf system and methods of laterally displacing a watercraft to generate wake. The lateral displacement system includes at least one pair of foils configured to be extended from a hull on a first side of the watercraft at a level of approximately the waterline. Upon forward movement of the watercraft with extended foils, the watercraft is rotated about its vertical axis toward the first side and generates waves sufficient for the conduction watersport activities on a second side of the watercraft. In some instances, foils are built into the hull and extended from this position, while in other instances the foils are attached to the hull using attachment structures. Rotation of the foils about an axis of rotation approximately perpendicular to a longitudinal axis of the watercraft alters the angle of attack of the foils relative to the waterline.

A multihull sailing vessel includes at least two buoyant hulls extending along their longitudinal axes, with the hulls being connected to each other and a first hydrofoil connected to the hulls and oriented transverse to the hulls. The first hydrofoil is movably coupled to the hulls between a first position above a resting waterline of the hulls and a second position below a lowest extent of the hulls. When the first hydrofoil is in the second position, a configuration of the first hydrofoil is adjustable to vary an amount of lifting force generated by the first hydrofoil when the hulls move forward through water when the first hydrofoil is in the second position.

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 marine catamaran craft, comprising at least one forward hydrofoil fixed to each of the catamaran hulls and at least one rear hydrofoil in which: At least one forward hydrofoil is arranged for shallowly submerged operation At least one rear hydrofoil is arranged for shallowly submerged operation at low speeds and for planing operation at higher speeds A rear part of each of the catamaran hulls remains wetted at all speeds.

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.