A fin box is provided for detachably attaching a fin to a surfboard. The surfboard has a nose and a tail at opposite ends. The fin has a groove base with one or more pins. The fin box includes one or more inner walls. The inner walls have (i) a hollow base with a width that is at least as great as a width of the groove base and a length that is at least as great as a length of the groove base, (ii) one or more recess parts disposed at locations that correspond to the locations of the pins of the fin, the recess parts extending in a direction that is substantially perpendicular to a length of the fin box, and (iii) one or more ditch parts that extend from the recess parts, the ditch parts extending in a direction that is substantially parallel to the length of the fin box and toward the tail of the surfboard. The recess parts and ditch parts are configured to allow the fin to be inserted into the fin box by (i) pressing the fin downward into the fin box until a bottom of the groove base is adjacent to the hollow base, and (ii) sliding the fin toward the tail of the surfboard, without any opposite motion toward the nose of the surfboard. The ditch parts are configured to, when the fin is attached to the fin box, hold the pins of the fin in the fin box.

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.

The present technology is generally directed to a fin assembly for watersport equipment, a watersport system including thereof, and a method of using thereof. In various embodiments, the fin assembly includes a support base and a foldable fin. The support base may be configured to attach the fin assembly to a surface of the watersport equipment. The foldable fin may include a fin portion configured to move between a folded position and a use position. The support base may have a locking member configured to lock the fin portion in and release the fin portion from the use position.

The present technology is generally directed to a fin assembly for watersport equipment, a watersport system including thereof, and a method of using thereof. In various embodiments, the fin assembly includes a support base and a foldable fin. The support base may be configured to attach the fin assembly to a surface of the watersport equipment. The foldable fin may include a fin portion configured to move between a folded position and a use position. The support base may have a locking member configured to lock the fin portion in and release the fin portion from the use position.

Disclosed is an apparatus, optionally mounted on a stand up paddle board, or surfboard, to lift the board above the water surface and support the board in a stable position above the water surface while a rider standing on the board and maintaining a speed in the water via paddling. In one embodiment, the apparatus includes a strut; a fuselage connected to said strut; a back foil portion connected to an aft end of said fuselage wherein the back foil portion includes two back wings extending outwardly from said aft end of said fuselage; and a forward foil portion connected to a fore end of said fuselage wherein the forward foil portion includes two front wings extending outwardly from said fore end of said fuselage and wherein the forward foil portion has a maximum thickness located at first distance from the fore edge of the forward foil portion.

A wheeled system for engagement with a surfboard is provided. Wheeled trucks are configured for removable engagement with a lower surface of a surfboard using mounting plates or recessed connections. The removable engagement of the trucks allow a rider to ride on support surfaces such as the sidewalk, and to remove the trucks to employ the surfboard in the water. The removable trucks may be retrofitted to existing surfboards with an elastic or mechanical engagement, or may be provided in combination with a surfboard.

A foil assembly for a watercraft includes a base assembly, a fin rotatably connected to the base assembly such that the fin can rotate longitudinally, and a slider attachment configured to connect to a fin box of a watercraft wherein the base assembly is configured to be removably disposed within the slider attachment such that the base assembly and the fin can be removed and rotated laterally to a folded position and still be retained by the slider attachment to the fin box.

A sliding fin for a surfboard includes a base having a planar tab with an upper flange, a large fin piece having a first indentation, and a small fin piece for mating face-to-face with the large fin piece. The second fin piece has a second indentation that forms a channel that has a cross-sectional shape corresponding to a cross-sectional shape of the planar tab and upper flange, the channel being longer than the width of the planar tab, the small fin piece being translucent to enable the planar tab in the channel to be seen, the large and small fin pieces being slidable relative to the base on the planar tab.

A personal watercraft body comprises a recess configured to receive similarly shaped cassettes. A first cassette may be motorized to propel the body relative to a body of water. A second cassette may be non-motorized and may include a storage space therein for storing personal items. An insert may be disposed between the cassettes and the recess to orient and fit the cassettes within the body.