The theory of a smooth faced blade causing less disturbance to the flow of water over the front face of the blade seemed to us to be in direct contradiction to basic hydrodynamic theory. Potential gains in hydrodynamic lift could be achieved if the back, not the front face of the blade, is free of impediments to the smooth movement of water in the direction of flow. It is not the front, but the back of the blade with its longer curved surface that accelerates the water flow and should provide a lifting force as the blade traverses out to the 90 degree stall position and back again during each stroke. By making the back surface "smooth" with the spine, or shaft attaching ridge parallel to the water flow, the blade would be more efficient and easier to handle.
