Sail for sail-board - has openings closable by sliding clasp fastening to reduce pressure on sail

摘要

The sailboard sail is furnished with openings which may have any known geometric shape. The openings may be located anywhere in the sail. The openings may be sealed off by sliding clasp fasteners which are made of plastics and may be operated on either side of the sail. The base of the opening is reinforced by an extra strip of material stitched across the patch. The openings are made to reduce the pressure on the sail in case of an increase in wind velocity.