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 hydrofoil wing attachment system that comprises a strut or struts and a hydrofoil wing fastening apparatus for various watercraft including, but not limited to, surf boards, kite boards, and stand up paddle boards. In one embodiment the system interfaces with legacy surfboard fin-box systems, thus allowing a user to interchange fins for hydrofoils and transform their watercraft into a hydrofoil watercraft. Other embodiment's of the system allow the implementation of a single-strut/wing combination and also a double-strut/wing combination among other variations. The design of the wing clamping apparatus allows the user to mechanically secure the wing and also configure the angle of attack of the hydrofoil wing. The modular design, configuration options, and high degree of interchangeability of the hydrofoil wing attachment system enables the user to experiment with multiple strut/wing configurations, wing/strut designs, and also the angle of attack.

A watercraft includes a hull, an opening extending vertically through the hull, and a support assembly configured to mount a propulsion mechanism to the watercraft. The hull at least partially defines the opening. The support assembly includes a rightward support device attached to the hull, positioned between a forward portion of the opening and a rearward portion of the opening, and at least partially defining a right lateral portion of the opening. The support assembly further includes a leftward support device attached to the hull, positioned between the forward portion of the opening and the rearward portion of the opening, and at least partially defining a left lateral portion of the opening.

An improved support for a fin extending downwardly from the undersurface of a water sport board provides detented rotational positioning of the fin at a selected one of a plurality of angular positions including a vertical position for use, a right side position and a left side position both of which protect the fin from damage during periods of nonuse, transport and storage and which avoid the need for removal and reattachment of the fin between periods of use and periods of nonuse, transport and storage.

An improved support for a fin extending downwardly from the undersurface of a water sport board provides detented rotational positioning of the fin at a selected one of a plurality of angular positions including a vertical position for use, a right side position and a left side position both of which protect the fin from damage during periods of nonuse, transport and storage and which avoid the need for removal and reattachment of the fin between periods of use and periods of nonuse, transport and storage.

A clamp assembly for connecting a rudder to an aquatic device having a body with a first end, a second end, a top and a bottom. A clamp having a screw connected to a pivot pin disposed within a clamp head is removably connected to the top of the body for selectively applying a clamping force on the body. The clamp handle in some bodies tapering to an end to allow placement within a retaining slot of a fin box.

A clamp assembly for connecting a rudder to an aquatic device having a body with a first end, a second end, a top and a bottom. A clamp having a screw connected to a pivot pin disposed within a clamp head is removably connected to the top of the body for selectively applying a clamping force on the body. The clamp handle in some bodies tapering to an end to allow placement within a retaining slot of a fin box.

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.

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 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.