A motorized fin booster system for surfboard or paddleboard or recreational small craft, consisting of at least one detachable motorized fin and at least one external, contour conforming and waterproof power supply are disclosed. The disclosed system allows for the addition and removal of electrically powered boost to nearly any board without permanent alteration of the board. The system integrates with widely used surfboard components; such as surf fins, leashes, ankle cuffs, and traction pads.

A modular, weight-shift controlled watercraft device is disclosed which includes a wireless handheld throttle controller comprising a body configured to avoid water intrusion, a throttle control interface configured to receive an input controlling a speed of the watercraft, a memory storing an operator profile setting, a wireless transmitter configured to communicate wirelessly with a microcontroller of the watercraft, a processor configured to communicate control information to the microcontroller of the watercraft via the wireless transmitter.

A method and system for providing a watercraft device are disclosed. The watercraft device comprises a board, a throttle coupled to a top surface of the board, a hydrofoil coupled to a bottom surface of the board, and an electric propeller system coupled to the hydrofoil. The electric propeller system powers the watercraft device using information generated from the throttle. A center of buoyancy in a non-foiling mode of the watercraft device and a center of lift in a foiling mode of the watercraft device are aligned.