Doel-Fin is the original hydrofoil developed by an aeronautical engineer to improve overall performance on all boats with outboard motors or outdrive units. high-strength plastic, each foil is designed to flex independently to absorb shock. The positive effects include greater stability, consistent planing at lower RPM, faster out-of-the hole performance, better gas mileage, steadier turns, higher top-end speeds and lower bow rise at all speeds. Doel-Fin is designed for use with small motors, big motors and inflatable dingies.