A wing, a method of controlling lift on a wing, and a system to produce lift on a wing are provided. The wing may include a fore-element, an aft-element, a pivotable linkage that operatively connects the aft-element leading edge to the fore-element trailing edge in a span-wise direction, and an actuator. The actuator may deflect the aft-element through a predetermined deflection angle about the pivotable linkage relative to the fore-element within less than or equal to two convective periods. The method may include deflecting a span-wise flap through the deflection angle in less than or equal to two convective periods to produce high lift. The system may include a sensor to detect an input and a controller to deflect the span-wise flap of the wing by the deflection angle in not more than two convective periods based on the received input signal.

This disclosure extends to systems, apparatus, and methods for sports board hydrofoil masts and mast-to-fuselage connection assemblies for hydrofoil sports boards. In one exemplary system, a hydrofoil mast formed as an elongated member may include a securing structure disposed in a lower region and a fuselage may include a recess into which the mast is inserted. A securing assembly may be disposed in the fuselage for actuation to secure the mast to the fuselage by interacting with the securing structure on the mast. The securing assembly may include a cam member or locking member and an actuating member. Unique hydrofoil masts constructed from composite materials having reinforcing metal members are disclosed and may be useful in the connection assemblies.

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.

This disclosure extends to systems, apparatus, and methods for quick release mast mounting assemblies for board mounted hydrofoil assemblies. In one exemplary system, a quick release mounting assembly may include board mountable base receiver for mounting to a sports board, which defines a longitudinal receiving recess. A resilient locking member is disposed at a front end of the base receiver. A separate mast connection member formed as a body configured for connection to an upper end of a hydrofoil mast, corresponds to the longitudinal receiving recess, and includes a counterpart structure for forming a secure connection with the resilient locking member. The mast connection member may include opposite shoulder or wing members that extend laterally orthogonal to the longitudinal axis thereof and the receiving recess may include counterpart slots for receiving these members. The resilient locking member may include a separate spring assembly or be a unitary member.

A modular, weight-shift controlled watercraft device is disclosed which includes: a modular board removably attachable to a power system. The power system includes a modular power supply system, and a modular propulsion system. The power supply system includes a housing including a battery. The propulsion system includes a modular strut, a modular propulsion pod, and a modular hydrofoil. In one embodiment, the power supply system is removably and mechanically attachable directly to the propulsion system.

A hydrofoil cavitating flow control structure includes a hydrofoil. A primary protuberant stripe is disposed in a middle position of a suction side of the hydrofoil, a plurality of symmetrically-distributed secondary protuberant stripes are disposed obliquely at both sides of the primary protuberant stripe, and the plurality of secondary protuberant stripes are uniformly and equidistantly distributed along the length direction of the primary protuberant stripe. By changing geometric parameters such as an included angle between the primary protuberant stripe and the second protuberant stripe, a ratio of cross section diameters and a distribution spacing of the second protuberant stripes along a chord length direction of the hydrofoil and the like, the shedding of cloud cavitation on a hydrofoil surface is effectively suppressed, and cavitation erosion and pressure pulsation generated by cavitation collapse is reduced, thus improving the operation efficiency and the service life of hydraulic machinery.

A sailing boat has an auxiliary hydrodynamic surface carried by a main boom connected in an oscillating way to a deck of the boat, about an axis of articulation parallel to the longitudinal direction of the boat. A drive system lowers the main boom on one side or the other of the boat in such a way that the hydrodynamic surface is selectively lowerable in a first operative position on one side of the boat to be put into the water on one side of the boat or in a second operative position on the other side of the boat to be put into the water on the other side of the boat. The boom is sized so that, when the hydrodynamic surface is located in one of its two operative positions on one side or the other of the boat, it is set at a lateral distance from the boat.

A sailing boat has an auxiliary hydrodynamic surface carried by a main boom connected in an oscillating way to a deck of the boat, about an axis of articulation parallel to the longitudinal direction of the boat. A drive system lowers the main boom on one side or the other of the boat in such a way that the hydrodynamic surface is selectively lowerable in a first operative position on one side of the boat to be put into the water on one side of the boat or in a second operative position on the other side of the boat to be put into the water on the other side of the boat. The boom is sized so that, when the hydrodynamic surface is located in one of its two operative positions on one side or the other of the boat, it is set at a lateral distance from the boat.

A hydrofoil wing attachment system that comprises a strut or struts and a hydrofoil wing fastening apparatus for various watercraft including, but not limited to, surf boards, kite boards, and stand up paddle boards. In one embodiment the system interfaces with legacy surfboard fin-box systems, thus allowing a user to interchange fins for hydrofoils and transform their watercraft into a hydrofoil watercraft. Other embodiment's of the system allow the implementation of a single-strut/wing combination and also a double-strut/wing combination among other variations. The design of the wing clamping apparatus allows the user to mechanically secure the wing and also configure the angle of attack of the hydrofoil wing. The modular design, configuration options, and high degree of interchangeability of the hydrofoil wing attachment system enables the user to experiment with multiple strut/wing configurations, wing/strut designs, and also the angle of attack.

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.