A wingsail for a powered watercraft comprising a first aerofoil element, a second aerofoil element, and a third aerofoil element, wherein each of the aerofoil elements is rotatable about an axis and has an aerofoil section with a centre of area which is closer to its leading edge than its trailing edge, and the aerofoil elements are movable to a configuration in which flow from the trailing edge of one of the first or third element is directed toward the leading edge of the second element, and flow from the trailing edge of the second element is directed toward the leading edge of the other of the first or third element.

A watercraft comprises a vehicle payload bay; a sail connected to the payload bay for propelling the watercraft in a foiling mode; and three or more hydrofoils connected to the payload bay. The hydrofoils are configured to provide control of the roll, pitch, and yaw of the watercraft and to elevate the vehicle payload by above a water surface when the watercraft is in the foiling mode. The hydrofoils can also provide control of roll, pitch, yaw, and elevation of the watercraft during the transition from a prone mode to a foiling mode. A mechanical propulsive system can be used for propelling the watercraft at least during transition from the prone mode to the foiling mode. The watercraft may not include a hull such that during the transition from the prone mode to the foiling mode, pitch and roll control are not substantially provided through the actions of gravity and buoyancy.

A rigid propulsion wing for a moving vehicle, including at least one first section and one second section, a first end and a second end each including attachment means for reversibly connecting to said moving vehicle, said first section and said second section being movable with respect to each other by means of articulating means such that said propulsion wing assumes, and moves from, at least a first deployed position to a second deployed position, and vice versa, in which deployed positions said first and second sections are arranged, substantially vertically, in the extension of each other, and in which said first end, or respectively said second end, are reversibly connected to said moving vehicle by means of the attachment means thereof.

An autonomous sailing vessel may include a hull, a mast, a sail, and a sail release device. The mast may be mechanically coupled to the hull. The sail may be mechanically coupled to the mast. The sail release device may be operably coupled to the sail and may be configured to automatically release the sail to spill excess wind. Alternatively or additionally, the sail may include a fore sail element coupled to the mast and an aft sail element rotatably coupled at a fore of the aft sail element to an aft of the fore sail element. In this and other embodiments, the autonomous sailing vessel may further include a camber control assembly to automatically set a camber angle between the fore and aft sail elements.

A wind-propelled vessel is described herein. The vessel includes at least one hull and at least one set of paired masts. Each paired mast of the at least one set of paired masts has a first mast located to one side of the vessel and a second mast located on the opposite side of the vessel. Also, each mast of the at least one set of paired masts has a spar located at or near the top of the mast. Moreover, each one of the spar located at or near the top of the mast extends inwards towards a center plane of the vessel, and an inward end of the spar is connected by a connector to another inward end of another one of the each one of the spar located at or near the top of the mast. In accordance with the illustrative examples provided herein, the connector imparts a dynamic force upon connected spars that responsively pulls the connected ones of the inward ends of the spars to their nearest position when tops of the masts to which the spars are fixably attached move away from a relative nearest position to a paired one of one set of paired masts.

A wind-propelled vessel is described herein. The vessel includes at least one hull and at least one set of paired masts. Each paired mast of the at least one set of paired masts has a first mast located to one side of the vessel and a second mast located on the opposite side of the vessel. Also, each mast of the at least one set of paired masts has a spar located at or near the top of the mast. Moreover, each one of the spar located at or near the top of the mast extends inwards towards a center plane of the vessel, and an inward end of the spar is connected by a connector to another inward end of another one of the each one of the spar located at or near the top of the mast. In accordance with the illustrative examples provided herein, the connector imparts a dynamic force upon connected spars that responsively pulls the connected ones of the inward ends of the spars to their nearest position when tops of the masts to which the spars are fixably attached move away from a relative nearest position to a paired one of one set of paired masts.

An adjustable foil having a suction surface and a pressure surface. The foil comprises an adjustable internal frame comprising a base, a plurality of articulately connected sections forming the suction surface of the foil, arranged consecutively from the leading edge of the foil to the trailing edge of the foil, and a plurality of frame struts, each articulately connected to the base and to a section of the plurality of sections. The foil is movable from a collapsed configuration to an expanded configuration by rotating the frame struts with respect to the base.

An adjustable foil having a suction surface and a pressure surface. The foil comprises an adjustable internal frame comprising a base, a plurality of articulately connected sections forming the suction surface of the foil, arranged consecutively from the leading edge of the foil to the trailing edge of the foil, and a plurality of frame struts, each articulately connected to the base and to a section of the plurality of sections. The foil is movable from a collapsed configuration to an expanded configuration by rotating the frame struts with respect to the base.

Cambering device for a profiled sail including:—an elastically deformable semi-rigid structure, including: —two length sections, extending one in front of the other, forming respectively a first length section secured to a first surface of the profiled sail, and a second length section secured to a second surface of the profiled sail, —a U-shaped connecting section, connecting together the two length sections terminating at the trailing edge by a tensioning of one of the two free ends, —a spacing system configured for working in compression and in tension, for maintaining a separation between the two length sections, —the action of the actuator, connecting together the two free ends of the semi-rigid structure.

Cambering device for a profiled sail including:—an elastically deformable semi-rigid structure, including: —two length sections, extending one in front of the other, forming respectively a first length section secured to a first surface of the profiled sail, and a second length section secured to a second surface of the profiled sail, —a U-shaped connecting section, connecting together the two length sections terminating at the trailing edge by a tensioning of one of the two free ends, —a spacing system configured for working in compression and in tension, for maintaining a separation between the two length sections, —the action of the actuator, connecting together the two free ends of the semi-rigid structure.