Abstract: A sailboard for sailing in water includes an elongated hull defining fore and aft and having a top and a bottom, and a panel integrally connected to the bottom of the hull near the aft end and extending beyond the aft end. The panel is relatively rigid at its distal end. An apparatus is connected to both the hull and the panel, and is operable for moving the distal end of the panel from a first position to a second position. The hull and the panel defining a relatively continuous flat surface for the first position and defining a relatively convex surface for the second position.

Abstract: The rear end of a slab-type hull of the sort utilized for windsurfing, and also as disclosed herein adapted to be used in the place of a slalom ski, is horizontally bifurcated to define a rigid upper deck portion and a flexible deflection panel extending beneath, and spaced from, the upper rear deck portion. The deflection panel can flex upwardly independently of the upper, rigid rear deck. Although the flexure of the deflection panel beneath the upper rear deck is functional without any further controls or modifications other than the independent flexure of the deflection panel itself relative to the overlying upper rear deck, its characteristics are enhanced by incorporating certain control features in the nature of a detent element which fixes the curvature of the deflection panel, and/or one or more stops, preferably spring-loaded, which determine the uppermost deflection of a certain portion or portions of the deflection panel.

Abstract: A surfboard having a resilient bottom panel which extends rearwardly beyond the rigid deck, this being accomplished preferably by splitting the rear portion of the board along the siderails to define a rigid rear deck spaced above a reinforced resilient panel defining the rearward continuation of the board bottom, there being a watertight flexible tailpiece fitted around the deck and over the bottom panel to form a smoothly contoured termination of the board at the rear and retain the hydrodynamic advantages of a conventional surfboard. The advantage of the invention lies in the ability of the trailing portion of the board bottom to flex in response to varying water pressure beneath as the board is being maneuvered, and one or more adjustable lever arms limiting the upward flexure may be provided beneath the rear deck.