A fin for use on a surfboard, the fin comprising: a leading edge, a trailing edge, and a base, the base comprising at least one mount for mounting the fin onto a surfboard; a first and a second outer fin surface which meet along the leading edge and the trailing edge and abut the base; and a first ridge protruding laterally from the first outer fin surface, and/or a second ridge protruding laterally from the second outer fin surface; wherein the shape and configuration of the fin creates an area of lower water pressure around and in front of the fin, as well as disrupting and/or reducing the size of trailing vortices, resulting in additional forward thrust for the board on which the fin is mounted.

A fin for use on a surfboard or another watercraft comprising a fin section that can be releasably coupled to the base of the fin, and the fin section can be slidably adjusted relative to the base in a direction towards the leading edge or the trailing edge of the fin. Following adjustment, the position of the fin section can be secured to the base with one or more locking means.

An electronically powered, light emitting fin used with a surfboard or paddleboard, or similar water sports board. The fin is configured to be attached to the water sports board to provide illumination under the board when using the device. The lighted fin may be particularly useful when using the water sports board at night to illuminate water beneath the board.

In one example, a watercraft includes a buoyant body in the form of a single piece structure sized and configured to support the weight of one or more users. The watercraft also includes a retractable fin connected to a pin that resides in a fixed location relative to the body, the pin including a side surface that is in contact with the body. The retractable fin is rotatable about the pin between an extended position and a retracted position, and the retractable fin includes an engagement portion that is engageable with a first portion of the body and with a second portion of the body. The retractable fin assumes the extended position when the engagement portion is releasably retained by the first portion of the body, and the retractable fin assumes the retracted position when the engagement portion is releasably retained by the second portion of the body.

A retractable fin system having a retractable fin and fin box is disclosed. An example retractable fin system includes a housing insertable into an opening in a watercraft board. The example retractable fin system also includes a retractable fin. The example retractable fin system also includes a bias to maintain the retractable fin in a default outward position from the housing. The bias retracts the retractable fin into the housing on contact with an outside force.

A water propulsion water rescue board with an integrated water propulsion jet to provide additional thrust for rescue maneuvers and different selectable thrust levels as needed during the maneuver. The water propulsion water rescue board includes a body having an upper surface and bottom surface, a length between nine feet and eleven feet from nose to tail, a thickness between 3.5 and 6 inches, and a water propulsion system integrated into the body including a water inlet on the bottom surface, and a water propulsion nozzle and propeller on the upper surface. An electric motor connects to rotate propeller for drawing water into the propulsion system and expels a pressurized column of water through the water propulsion nozzle. A removable rechargeable battery is connected with the electric motor and a controller with a user control pad on the top surface of the body to allow the user to control the operation of the water propulsion system.

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 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.

Disclosed is a method for controlling a hydrofoil board powered by a motor driven propeller. The motor is controlled by a hand controller configured with user selectable operating pre-sets including a first operating pre-set, wherein the board is accelerated to a first speed which is less than that required for the board to hydrofoil, and a second operating pre-set, wherein the board is accelerated to a second speed sufficient for the board to hydrofoil. Alternatively, the operating pre-sets may limit the motor power. A system for operating a hydrofoil board is also disclosed, which includes a propulsion control unit comprising a propulsion source, and a hand controller configured to receive a first user input and a second user input and to transmit the user inputs to the propulsion control unit.