An electric hydrofoil board having a submersion-cooled powertrain is provided. A powertrain assembly, which includes a motor housed in a motor assembly and an electronic speed controller housed in a nose cone assembly that is fastened to the motor assembly, is attached to a lower end of a mast of the hydrofoil board so that the powertrain assembly remains submerged at all times during normal use of the hydrofoil board in a body of water. The flow of water around the powertrain assembly during normal use cools heat-generating components of the electronic speed controller and motor.

A steering apparatus of a hydrofoil includes first to fourth propulsion portions, a central connecting portion, a left hydrofoil, and a right hydrofoil. Among the first to fourth propulsion portions, the first propulsion portion 41 and the third propulsion portion are disposed on the left side, and the second propulsion portion and the fourth propulsion portion are disposed on the right side. The central connecting portion connects the first to fourth propulsion portions with each other via a first fixing portion and a second fixing portion. A left hydrofoil and a right hydrofoil are respectively attached to outer sides of the central connecting portion via the first fixing portion and the second fixing portion.

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 water sports device is provided, and includes at least one propulsion device which has at least one motor. The motor can be controlled by a control unit and is provided for propelling the water sports device. The parts of the propulsion device are arranged on sides of the foil and/or retaining device or—if separate connection elements are arranged between these two devices—between these two devices, and can be moved with the foil device from a starting and/or resting position into the operating position and back. In order to propel or pull the water sports device, the device has its own propulsion device. This is part of the retaining and/or foil device, which can move relative to the floating body, in that at least one propulsion element in the form of a propeller or impeller accelerating water against the principal direction of movement is moved with the respective device (retaining and/or foil device).

A water sports apparatus is provided, and includes a propulsion device which is provided for the propulsion of the water sports apparatus and whose motor, arranged on the float-body side, is connected in terms of drive to at least one propulsion element via an angularly and/or longitudinally movable propulsion train. The angularly and/or longitudinally movable propulsion train allows the propulsion element to be positioned optimally on the body-of-water side. The motor is arranged in a region which does not cause any body-of-water-side resistance in the operating position with a float body lifted off from the water surface. That part of the water sports apparatus which is situated in the water is optimized with regard to the design which is relevant to flow resistance in the water.

A water sports device is provided in which a propulsion device has at least one sensor arrangement which is usable for position determination. A control unit of the water sports device is designed for generating control signals on the basis of signals from the sensor arrangement for the purpose of geofencing and/or homing. One or more controllable elements of the water sports device are activated by means of the control signals. Such elements may include a motor of the propulsion device, movable means for generating an alignment of a water jet (e.g. a wing, motor, rudder blade, a fin and/or nozzle), and/or retractable and extendable elements (a centerboard, a holding and/or hydrofoil device) which influence the floating properties of the water sports device.

A holding apparatus is provided by way of which a hydrofoil surface apparatus can be retracted and extended and/or folded, out of a rest and/or starting position into its operating position and/or out of the operating position into the rest and/or starting position. Such actuation can take place manually by way of a person operating the water sports device, with the advantage of simpler transportability of the water sports device. The water sports device can already be placed in water close to the bank or beach, and can be guided or moved from there in the direction of deeper water. As soon as sufficiently deep water is reached, the hydrofoil surface apparatus can be transferred via the holding apparatus into the operating position.

An upweller array configured to be disposed in a body of water and that has one or more upweller systems. The one or more upweller systems include a buoy configured to float on the surface of the body of water, a tether coupled to the buoy and a hydrofoil rotor coupled to the tether. The hydrofoil rotor is configured to be disposed in the body of water based on a length of the tether.

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 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.