Hollow oar blade with hinged panels - has panels folding out of way on return stroke

摘要

The oar consists of a rectangular frame with stiffening brackets holding the frame to a tubular shaft. The rectangular frame has a central rib parallel to the long sides. The edge of the central rib has three hinges equally spaced along it. Two panels which cover the rectangular frame are connected to the hinges on either side of the rib, so as to fill the space of the rectangular frame. The water pressure keeps the oar solid on the pressure stroke and allows the panels to flap out of the way on the return stroke.