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 hydrofoiling watercraft is disclosed that includes a board having a top surface for supporting a user and a bottom surface. Extending from the top surface of the board is a handlebar. Extending from the bottom surface of the board is a hydrofoil including a strut and a hydrofoil wing. A propulsion system is attached to the hydrofoil.

Systems, apparatus, and methods for hydrofoil assemblies with planing blades that may be adjusted, and securely maintained in varying tilts with respect to a support member, using a curved indexing system with a curved ridge and a counterpart groove that utilize interacting position retaining elements to retain a desired tilt in different adjustable positions. In one illustrative system, a planing blade may have a convexly curved ridge disposed on a surface thereof with a series of transverse grooves disposed in the curved ridge. A support member may have a counterpart concavely curved receiver with a series of counterpart transverse grooves formed therein. When a user places the planing blade in position with the convex ridge contacting the concave receiver, the blade may be tilted to a desired position. The counterpart transverse grooves interconnect to provide an indexed positive interlock, securely maintaining the blade in the desired position.

Systems, apparatus, and methods for hydrofoil assemblies with planing blades that may be adjusted, and securely maintained in varying tilts with respect to a support member, using a curved indexing system with a curved ridge and a counterpart groove that utilize interacting position retaining elements to retain a desired tilt in different adjustable positions. In one illustrative system, a planing blade may have a convexly curved ridge disposed on a surface thereof with a series of transverse grooves disposed in the curved ridge. A support member may have a counterpart concavely curved receiver with a series of counterpart transverse grooves formed therein. When a user places the planing blade in position with the convex ridge contacting the concave receiver, the blade may be tilted to a desired position. The counterpart transverse grooves interconnect to provide an indexed positive interlock, securely maintaining the blade in the desired position.

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 surfboard fin assembly for the flush incorporation into a surfboard body that allows for adjusting the depth the fin extends below the surfboard. It has a biasing means that maintains the fin in the down position yet allows upward movement upon the application of upward force such as when the fin is struck from below. The fin is perpendicularly affixed to a hinge body that is pivotally housed in an open ended fin box that is integrated into the volume of the surfboard body. A means for tensioning is releasably attached at a distal end to the hinge body and at a proximal end to the surfer's ankle. The height of the fin is adjustable through the means for tensioning and sets the performance of the surfboard to the surfer's desired level of directional control depending on their type of surfing. The fin or fin and hinge body are interchangeable with other design of fins.

A surfboard fin assembly for the flush incorporation into a surfboard body that allows for adjusting the depth the fin extends below the surfboard. It has a biasing means that maintains the fin in the down position yet allows upward movement upon the application of upward force such as when the fin is struck from below. The fin is perpendicularly affixed to a hinge body that is pivotally housed in an open ended fin box that is integrated into the volume of the surfboard body. A means for tensioning is releasably attached at a distal end to the hinge body and at a proximal end to the surfer's ankle. The height of the fin is adjustable through the means for tensioning and sets the performance of the surfboard to the surfer's desired level of directional control depending on their type of surfing. The fin or fin and hinge body are interchangeable with other design of fins.

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.

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.

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.