On the simplest designs of rotating paddle boats designed by Leonardo, the movement of the paddles is entrusted to the arms of the sailors driving the boat, while in this one the rotation arises from the alternating movement of the legs of a single sailor.
The operator, leaning on the central mechanism, placed his feet on two boards that acted as pedals and moved his feet up and down. The alternating motion was converted into rotary motion of the wheel axle, which, moving in one direction, would give the boat a rectilinear motion.