A watercraft (10) including a board (12), a mast (16) extending below the board, (12) the mast (16) carrying a foil (20) and a propeller (30) that is driven by a motor (32), the motor (32) being carried in a tube (18) connected to or extending from the mast (16), wherein a motor controller (34) is also positioned within the tube (18). In this manner, heat generated by the motor controller during use is dissipated into the water through which the watercraft is travelling. The watercraft (10) may also have a receptacle for holding lubricant, the receptacle being located above the motor, wherein the mast has a conduit that provides fluid communication between the receptacle and the lubricant lubricating the motor and/or driveshaft such that lubricant in the receptacle provides a hydrostatic head of pressure to prevent or minimise water ingress around a propeller seal or a driveshaft seal located adjacent a region where the driveshaft exits into the water.

This present invention relates to an electric fin and a water sports instrument, wherein the electric fin comprises a housing extending along a first direction and having a water inlet cavity; and a propeller and a guide member sequentially arranged in the first direction, wherein the propeller is located in the water inlet cavity, at least part of the guide member is located in the water inlet cavity, the water flow in the water inlet cavity flows out of the guide member; the propeller is provided with a propeller shaft and a plurality of blades, the propeller shaft extends in the first direction, and the plurality of blades are arranged on the propeller shaft in the circumferential direction; the guide member is provided with a guide shaft and a plurality of flow deflectors, the guide shaft extends in the first direction and the plurality of flow deflectors are arranged on the guide shaft in the circumferential direction; the outer contour enclosed by the propeller shaft and the guide shaft shows a projection in a second direction, whose size in a third direction gradually decreases along a fourth direction. The electric fin of the present invention has sufficient power and good guiding performance.

This present invention relates to an electric fin and a water sports instrument, wherein the electric fin comprises a housing extending along a first direction and having a water inlet cavity; and a propeller and a guide member sequentially arranged in the first direction, wherein the propeller is located in the water inlet cavity, at least part of the guide member is located in the water inlet cavity, the water flow in the water inlet cavity flows out of the guide member; the propeller is provided with a propeller shaft and a plurality of blades, the propeller shaft extends in the first direction, and the plurality of blades are arranged on the propeller shaft in the circumferential direction; the guide member is provided with a guide shaft and a plurality of flow deflectors, the guide shaft extends in the first direction and the plurality of flow deflectors are arranged on the guide shaft in the circumferential direction; the outer contour enclosed by the propeller shaft and the guide shaft shows a projection in a second direction, whose size in a third direction gradually decreases along a fourth direction. The electric fin of the present invention has sufficient power and good guiding performance.

The present invention provides devices and kits for modifying a standard surfboard into a motorized surfboard, utilizing a detachable modular underwater power unit, wherein said underwater power unit is configured to be attached to various standard fins or a fin unit, and wherein the underwater power unit is further configured be utilized for diving and/or swimming applications.

The present invention provides devices and kits for modifying a standard surfboard into a motorized surfboard, utilizing a detachable modular underwater power unit, wherein said underwater power unit is configured to be attached to various standard fins or a fin unit, and wherein the underwater power unit is further configured be utilized for diving and/or swimming applications.

A self-contained battery assembly is provided that is configured to be removably coupled to a watercraft. The battery assembly comprises a waterproof housing including a top portion and a bottom portion that houses a plurality of battery modules. The battery assembly includes a plurality of battery separators manufactured from a material to provide passive protection against thermal event propagation and an electronics module. Each of the battery modules is surrounded on four sides by the one or more of the plurality of battery separators. The plurality of battery separators are disposed within the housing and in physical contact with the top portion and the bottom portion.

A hydrofoil watercraft, in particular, a hydrofoil board is described herein. The hydrofoil board may comprise one or more of a body, a hydrofoil assembly, and/or other components. The body may have one or more of a deck surface configured to support a rider, a bottom surface opposite the deck surface, and/or other surfaces and/or features. The body may comprise a fore portion having a planing surface forming part of the bottom surface. The body may have an aft portion having an aft bottom surface forming part of the bottom surface. The fore portion may be toward a front end of the board. The aft portion may be toward a rear end of the board. An aft cross-sectional thickness between the deck surface and the aft bottom surface may be less than a fore cross-sectional thickness between the deck surface and the planing surface.

The systems and methods described herein provide hands free motor control mechanisms based on the natural and inherent movements associated with an activity of interest, and can be combined with gestures or verbal communication based upon pre-defined movements by the participant.

A self-propelled hydrofoil surfboard includes a surfboard having a mast mounted to the lower surface of the surfboard, a selectively controllable thruster mounted at a lower end of the mast, a controller and a battery to supply power to the controller and thruster, the controller cooperating with a remote controller adapted to give control inputs to the controller and to be carried when in use by a rider, navigation lights mounted around at least a portion of the circumferential edge of the surfboard, and wherein the mast may have an adjustable length.

A floatation device may include a bow section and a tail section pivotally connected to the bow section by a kingpin assembly. The kingpin assembly may be configured to include a positive kingpin inclination angle or a negative inclination angle that determine the yaw direction of the floatation device. A user may control the tilt or roll of the floatation device to offset a yaw direction and maintain a straight line tracking course.