A fin (1) for a windsurf board is constructed from fibers (5) which have a preferred fiber direction with the majority of the fibers lying in this direction, the preferred direction extending at an acute angle (a) to the longitudinal axis (4) of the profile of the fin blade (2). This allows the fin to distort and to change the properties of its profile in a defined manner when loaded.

A sailboard has a pair of skegs extending downwardly from a bottom surface thereof generally adjacent a rear of the sailboard. The pair of fins extend in a vertical orientation parallel to a centerline of the sailboard. A retractable fin is mounted adjacent the rear of the sailboard. The sailboard has a mast base adjacent an aerodynamic center thereof. A tunnel area is formed at a bottom surface of the sailboard adjacent the rear of the sailboard between the pair of skegs.

A swept forward wing for aircraft comprising an inner wing portion and an outer wing portion in which the upper surface curvature of the inner wing portion is designed to create three dimensional flow thereover to manipulate the sweep of the isobars and prevent desweeping thereof, the inner wing portion including a wing root section (4) having a far aft maximum thickness position (14) coupled with high camber in the region of said maximum thickness position, said wing root section (4) further including a negatively cambered leading edge portion (10) and a nose-down twist configured to suppress high leading edge velocities, the combination of thickness and camber forms aft of the leading edge region (10) causing the flow to accelerate until a maximum velocity is reached relatively far back on the wing.

The present invention relates to a wing tip extension (7) for a wing, having an upper and a lower surface (10 and 11) and a leading edge and a trailing edge (12 and 13), the geometries of which are such that between a connection region (8), for connection with a wing, and the tip (9) of the wing tip extension (7) there is provided a continuous increase of the local dihedral, a continuous increase both of the sweepback angle of the leading edge (12) and also of the trailing edge (13), and a continuous decrease of the chord of the wing tip extension (7), and in that the wing tip extension (7) in the connection region (8) carries on from the wing in substance continuously. The wing tip extension (7) in accordance with the invention thereby ensures a significant reduction of the overall drag.

A hydrofoil sailboard comprising a conventional sailboard, without the usual tail skeg, equipped with two hydrofoils arrayed in a canard configuration, the combined lift of the foils being sufficient to hold the board clear of the water at operational speeds. The main foil, mounted beneath the rear of the board is designed to ride fully submerged and to support the bulk of the weight of the board and sailor. The much smaller canard foil, mounted beneath the front of the board is designed to ride at or near the water surface, and its purpose is control and balance. The main foil is connected to the board by a supporting foil which is provided with ventilation fences. The canard is rigidly connected to the board by a support comprising a rod about which a streamlined fairing is free to swivel. A seal between the fairing and the rod prevents airflow to the canard along the inside of the fairing. The purpose of the swiveling fairing is to eliminate canard ventilation along the outside of the support, to reduce drag, and to enhance steering. The canard is designed to rapidly shed air bubbles that may lodge on it when it is submerged.