An improvement to a conventional surfboard includes an impeller and an electric motor contained primarily within the body of the surfboard, whereby performance of the surfboard is substantially unaffected by the presence of the impeller and the electric motor. The electric motor is operatively connected...http://www.google.fr/patents/US7993178?utm_source=gb-gplus-shareBrevet US7993178 - Powered surfboard for preserving energy of a surfer during paddling
Powered surfboard for preserving energy of a surfer during paddling
