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.

A Kinetic Infinity Mount System (KIMS) comprises an outer housing, first and second outer gears, first and second inner gears, two pins, two screws, two mechanical collars, and a fin box. The KIMS allows different reusable and removable fins to be mounted onto a surfboard or other waterborne vessels. The KIMS provides dynamic, simultaneous adjustment and setting of a toe angle and a camber angle of the fin. The fin box includes two screw holes at each end and four screw holes along the side. Users choose from multiple settings of positive or negative toe angle or camber angle for each fin mounted into the surfboard. Camber and toe angles, in both positive or negative directions, can be adjusted simultaneously or separately to the user's preference. The KIMS allows different types of fins by FCS, Futures or similar, rectangular based fins to be mounted into the fin box and adjusted to desired configuration.

The invention relates to a watercraft for transporting at least one person on a water surface, comprising an input device for providing a control instruction, wherein the control instruction depends on an input movement of the person and the input movement can be carried out during travel with the watercraft, furthermore comprising a control device for providing a change and thus a selective increase and decrease of the lift force as a function of the control instruction, furthermore having a transmission device for transmitting the control instruction from the input device to the control device, furthermore having a steering device for providing a change in direction of the watercraft taking place along the water surface as a function of a steering movement by the person, wherein a holding device is provided for enabling a supporting function for the person operating the watercraft, wherein the input movement can be carried out independently of the steering movement and/or the supporting function.

The invention relates to a watercraft for transporting at least one person on a water surface, comprising an input device for providing a control instruction, wherein the control instruction depends on an input movement of the person and the input movement can be carried out during travel with the watercraft, furthermore comprising a control device for providing a change and thus a selective increase and decrease of the lift force as a function of the control instruction, furthermore having a transmission device for transmitting the control instruction from the input device to the control device, furthermore having a steering device for providing a change in direction of the watercraft taking place along the water surface as a function of a steering movement by the person, wherein a holding device is provided for enabling a supporting function for the person operating the watercraft, wherein the input movement can be carried out independently of the steering movement and/or the supporting function.

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 invention relates to a movable fin assembly, which includes a housing attachable to an underside of a watercraft and a rotation and pivoting mechanism. The mechanism positioned inside the housing and movable about two axes of rotation. The mechanism further has a fin locating position, thereby a fin provided at the fin locating position is capable of moving about the two axes of rotation via the mechanism, such that the fin's toe angle and camber angle changes when moving through the water. The invention further extends to an interchangeable self-aligning fin and static fin kit which includes a rotation and pivoting mechanism and a static member shaped and dimensioned to correspond with an interior of the housing. The static member and the rotation and pivoting mechanism interchangeably receivable by the housing in order to selectively provide a dynamic or static fin on the underside of the watercraft.

A retractable fin watercraft accessory that provides steering and tracking for a watercraft such as stand-up paddle boards. The retractable fin system gently retracts as it comes in contact with subsurface objects such as rocks, logs and such, allowing the watercraft to freely pass over the object. The system includes a sloped leading edge which can more easily slide past an obstacle. The retractable fin system simply attaches to the watercraft's existing fin mounting box and can be removed from the watercraft without altering the original state of the watercraft prior to being attached. No drilling, welding, gluing or other such custom fabrication is required. The system allows for quick interchangeability between the retractable fin and various rigid style fins, depending on the user's preferences.

A surf board which may be broken into two parts, into an inflatable body component and a drive component, wherein the drive component has an electrical drive and forms, or at least partially forms, a tail of the surf board. The surf board can be controlled particularly well by the formation of the drive component as the tail, and it has a higher degree of efficiency. Furthermore it is simple and manageable to transport if the air is let out of the body component.

A paddle for stand-up paddle boards and other water craft includes a paddle blade at a lower end of the paddle shaft and a skeg/fin extending from the lower edge of the paddle blade. A method and system for transporting a user across water or other surfaces has a board or other water craft for the user to stand/sit upon and a paddle with the skeg/fin extending from the paddle blade.