A foil board with two hydrofoils is described. A first version has a single mast supporting both a leading hydrofoil wing and a trailing stabilizer wing connected to each other with a fuselage. A second version has two masts, with a front mast supporting a stabilizer wing and a rear mast that supports a hydrofoil, or with the front mast supporting the hydrofoil and the rear mast supporting the stabilizer wing. Both versions have a removable propulsion unit, which allows the user to easily remove the propulsion unit for cleaning, maintenance, repair, or even to remove it temporarily so that the foil board can be used for non-motorized applications.

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.

The present invention relates to a resiliently flexible fin for a surfboard or another surface watercraft, the resiliently flexible fin comprising a titanium or titanium alloy core and an opening in the trailing edge that enables a portion of the rear of the fin to resiliently flex against the force of water as the surfboard is turned, which can generate additional forward thrust for the surfboard as the surfboard exits the turn and the fin returns to its unflexed state displacing water in its path with force.

A watercraft fin removal tool for facilitating the removal of a detachable fin coupled to a watercraft body. The tool comprises an elongate body having a fin engagement head at one end and a handle at an opposing end. In use, the head is configured to engage the fin such that a sufficient leverage force may be applied to the fin by the user at the head via the handle to detach the fin from the watercraft body. In the preferred embodiment, the tool is designed for the removal of detachable surfboard fins. But, it may also be configured to remove fins from other watercrafts, such as wakeboards, paddleboards and the like.

A personal watercraft includes a floatation member, a thrust assembly, a steering assembly, and a braking assembly. The assemblies may be actuated either mechanically or electrically. The thrust assembly is human powered, solar powered, or electric powered. The thrust, steering, and braking assemblies can be added after-market to an existing stand-up paddle board (SUP), or built into one or a plurality of SUPs during initial manufacturing. When the thrust assembly is human powered, it is leg or arm powered. When the thrust assembly is leg powered, the legs can move backward and forward in a sliding motion, up and down in a stomping fashion, or move in a loop trajectory. When the thrust assembly is arm powered, the arms can move forward/backward together or separately. The thrust assembly includes one or a plurality of paddles or flippers that are positioned to the side or under the SUP.

A Kinetic Infinity Mount System (KIMS) allows different reusable and removable fins to be mounted into the cavity of a finbox of a surfboard or other waterborne vessels with the dynamic feature of toe in or toe out and camber in or camber out simultaneous or separate adjustments. Toe angle adjustment is accomplished by an outer, square, male gear which can be moved in and out of a female, circular track. At the back of the outer gear is the circular, female gear. Camber angle adjustment is accomplished by moving a front and rear male, circular gear in and out of the female side of the outer gear along the same circular plane as the outer gear. The KIMS allows different types of fins to be mounted into the finbox and then adjusted about its own axis and around a plane.

A water ski system includes an elongate ski body member having an aft end portion with a mounting face. Interchangeable tail members having an engagement face are configured to be selectively mounted to the ski body such that the engagement face of the tail member abut the mounting face of the ski body member. Attachment hardware removably fixes the selected tail member to the ski body member. The interchangeable tail members may have a variety of shapes and lengths, allowing a skier to customize the water ski to accommodate differing water ski styles, water, conditions, and skill levels.

A water ski system includes an elongate ski body member having an aft end portion with a mounting face. Interchangeable tail members having an engagement face are configured to be selectively mounted to the ski body such that the engagement face of the tail member abut the mounting face of the ski body member. Attachment hardware removably fixes the selected tail member to the ski body member. The interchangeable tail members may have a variety of shapes and lengths, allowing a skier to customize the water ski to accommodate differing water ski styles, water, conditions, and skill levels.

This invention is directed toward a fin box capable of accepting either a Futures or an FCS fin without the need for any additional products being added to either the fins or the fin box. The box has an internally-adjustable wedge that can force the bottom of a fin into an indent, thereby giving it a cant or angle. The box also has channels for both FCS and Futures fins, such that a user can easily exchange either brand of fin without adding or subtracting items from the fins or fin boxes. Another embodiment of the invention provides a fin base with a wedge angle that compresses an underlying wedge, thereby wedging the fin in the fin box. A further embodiment has a button on the fin that compresses a springy material as it passes over a fin box lip, thereby removably securing the fin in the fin box.

This invention is directed toward a fin box capable of accepting either a Futures or an FCS fin without the need for any additional products being added to either the fins or the fin box. The box has an internally-adjustable wedge that can force the bottom of a fin into an indent, thereby giving it a cant or angle. The box also has channels for both FCS and Futures fins, such that a user can easily exchange either brand of fin without adding or subtracting items from the fins or fin boxes. Another embodiment of the invention provides a fin base with a wedge angle that compresses an underlying wedge, thereby wedging the fin in the fin box. A further embodiment has a button on the fin that compresses a springy material as it passes over a fin box lip, thereby removably securing the fin in the fin box.