The test-pilot of Supermarine's Schneider-winning seaplanes reported how with ever-increasing power from Rolls' engine, application of full rudder was required throughout the take-off due adverse effects of torque ~ which will have loaded one float more than the other to the extent it acted like a pivot-point around which thrust was being applied. This can be used for advantage to simplify maritime drones, most obviously with a mono-ski but also to a practical extent with catamarans. The illustration shows how beside applying asymmetric thrust, contra-rotating propellers apply a load on the opposite hydro-ski to facilitate a turn... to the right here. Finally by applying fixed rudder surfaces to the rear of each ski within the efflux of their propeller ~ or an offset to each motor ~ a further positive vector holds out the prospect of substantial control in the absence of moveable surfaces and servos.
