Electro Propulsion by Hy-Generation - METS Video 

Hello Rob, the propeller switches seamlessly from a low pitch (= high push) configuration when you start or when you have a heavy payload, to a high pitch (high speed) configuration when the boat accelerate. => more static push, and increased top speed. Also you never get a rough 45° incidence angle between the blade and the water lines, which would only create washing machine effect and no push. => Efficiency gains. Numbers depends on the convventional propeller compared. we often have +40% static push, +15% top speed, + 30% energy.