Surfing has been in vogue as a pastime, recreational activity and sport for some time. In order to function adequately a surfboard has on its underside at least one fin. Usually three fins are used, two side fins towards the rear of the board and a central fin between the side fins and often placed generally rearward of the side fins. The fin or fins assist in creating stability and reduce unwanted leeward motion. Fins, keels and centerboards are used in other waterborne vessels for similar purposes. However the fin, keel or centerboard itself in its contact with the water creates drag and reduces the performance of the surfboard or other waterborne craft.
USPTO Backgrounds
USPTO Backgrounds