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.

A swimming propulsion device. The swimming propulsion device includes a fuselage at least one propulsor pivotally connected to the fuselage, and in some embodiments, at least one stabilizer affixed to the fuselage. The device also includes a swimmer connection mechanism removably attached to the fuselage by a locking mechanism whereby the swimmer connection mechanism connects a swimmer to the device, and a control mechanism installed within the propulsor. A method for efficient swimming is also disclosed.

One embodiment of submerged superventilated blades (101) that provide hydrodynamic force to a vessel or aircraft (117) that can lift it above the surface of the water (106) at high speed by creating thrust with a wetted high pressure surface (111), the low pressure surface (112) being covered with a gas filled void in the liquid, thus preventing sudden loss of lift as speed increases due to cavitation or surface venting. Other embodiments are described and shown.

A three stage watercraft for operation in the water as a traditional boat at low speeds in stage one, for operation on the water's surface at mid-range speeds at stage two, and for traveling in ground effect at higher range speeds is disclosed. The three stage craft includes a hydro-wing 12, at least a single hydrofoil 13 to aid with lift from stage one to stage two, and a pair of outboard floats or hydro-floats 16a, 16b supported by the hydro-wing 12, which are also designed to aid with lift from stage one to stage two. A gyration rotor 14 to aid with lift from stage one to stage two may also be provided as may a pair of pivotally mounted air propellers which aid in lift and propulsion by varying their operational angle relative to the plane of travel of the craft.

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.

The human powered hydrofoil bicycle includes multiple subsystems integrated together including a structural frame subsystem with associated steering and tiller module, a hydrofoil subsystem to provide vehicle lift, and a powertrain subsystem. The structural frame subsystem may be fitted with buoyancy modules to provide the overall vehicle with a near neutrally buoyant character. The structural frame subsystem also supports a seat for an operator and provides structural support for the steering and tiller module for the hydrofoil subsystem and the drivetrain subsystem. The hydrofoil subsystem includes multiple hydrofoil elements at lowermost portions of the vehicle. These hydrofoil elements generally include in a preferred embodiment a larger rear foil and a smaller front foil. The powertrain subsystem generally includes pedals rotatably supported on the vehicle at a convenient location for engagement and driving by feet of an operator. Power transmission elements extend from the pedals down to a prime mover such as a propeller.

A passively controlled fluid foil has a span; and a rigid spar extending in the spanwise direction, a cellular material and a flexible outer surface defining a profile of the outer surface of the foil and encapsulating the cellular material and the spar.

A watercraft and a waterproof electronics container are provided. The watercraft includes a flotation portion. A strut is removably affixed to a portion of the watercraft. A first connector portion is mounted to the upper end of the strut. A waterproof electronics container includes a second connector portion is disposed such that the second connector forms at least one electrically conductive pathway with the first connector portion when both are affixed to the watercraft. The waterproof electronics container is removably affixed to the said watercraft. In one aspect, the waterproof electronics container houses a power source capable of powering an electric motor that propels the watercraft.

A flexible coupling mechanism may be used to suspend a structural component, such as a propulsion pod, from a support member, such as a strut of a hydrofoil watercraft. The flexible coupling mechanism may include multiple vibration isolating mounts configured to extend through the support member to suspend the structural component. The vibration isolating mounts may include a plurality of elastomeric bushings configured to prevent direct contact between a component rigidly coupled to the support member and a component rigidly coupled to the structural component. The elastomeric bushings may include a tapered outer profile configured to provide a nonlinear force feedback profile in response to rotation of the support member relative to the structural component.