What powered boat did Leonardo da Vinci design using paddle wheels?

Leonardo da Vinci designed a paddle boat powered by paddle wheels.

His sketches show a boat with paddle wheels turned by a mechanical system. As the wheels rotated, their blades pushed against the water and produced forward motion. The concept attempted to replace or supplement rowing with a machine-driven propulsion method.

Leonardo explored the design while studying transport and engineering. His notebooks contain many studies of water movement, boats, gears, and mechanisms. The paddle boat was one of several ideas intended to make movement more efficient, especially when human labor was limited.

The design was not a modern steamboat because Leonardo did not have a steam engine. It also differs from a propeller-driven boat, which uses a submerged screw rather than rotating paddle wheels. Paddle-wheel propulsion later became practical with steam power, but Leonardo’s Renaissance concept remained a mechanical proposal.