A fin plug (10) for installation in a water craft, said fin plug (10) including: a first open cavity (20) adapted to receive a base portion (15) of a water craft fin (50); and, a resilient biasing rod (30) and a protruding member (35) cooperating with the biasing rod, said protruding member being adapted to abut the base portion (15) of said fin (50) when received in said first open cavity (20); wherein said biasing rod and protruding member are adapted to apply a force to the base portion of said fin to inhibit removal of said fin from said first open cavity.

A hydrofoil for a watercraft comprises a mast as well as a front wing and a rear wing, which are arranged, based on the forward travel direction, one behind the other at a free end portion of the mast. The rear wing is designed as an annular wing and, in addition, includes at least one tubular portion, which is oriented to the forward travel direction in such a way that water is able to flow through said tubular portion counter to the forward direction of travel.

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.

Hydrofoil assemblies that can be attached to a board used for watersports are disclosed herein. A hydrofoil assembly may include, for example, a mast a coupleable to a fuselage at a lower portion of the mast and coupleable to a board at an upper portion of the mast, and front and rear wings coupleable to the fuselage. A hydrofoil mast may include, for example, first and second composite sections bonded together to form a hollow load-bearing mast structure. Leading and trailing elements made of a material that is softer than the composite mast structure may be adhered to the mast structure to complete a hydrodynamic profile of the mast.

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 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.

An assembly includes a fin and a fin mounting box for a water sports board. The mounting box is mounted to the board and has an outwardly facing channel formed therein. The fin includes a fin base and a body extending from the base. The fin base is shaped to be received in the channel. The channel includes channel engagement formations, and the fin base includes corresponding fin base engagement formations which engage the channel engagement formations when the fin base is inserted into the channel so as to retain the fin to the mounting box. The assembly includes a locking tab received in the channel to prevent movement of the fin base in the channel and disengagement of the corresponding channel and fin base engagement formations.

An assembly includes a fin and a fin mounting box for a water sports board. The mounting box is mounted to the board and has an outwardly facing channel formed therein. The fin includes a fin base and a body extending from the base. The fin base is shaped to be received in the channel. The channel includes channel engagement formations, and the fin base includes corresponding fin base engagement formations which engage the channel engagement formations when the fin base is inserted into the channel so as to retain the fin to the mounting box. The assembly includes a locking tab received in the channel to prevent movement of the fin base in the channel and disengagement of the corresponding channel and fin base engagement formations.

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.

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.