Leonardo da Vinci’s paddle boat concept combined a boat with a paddle-wheel propulsion system.
Leonardo designed watercraft that used rotating paddles to push against the water. A crank and gear arrangement could transmit human effort to the paddle wheels, allowing a vessel to move without relying entirely on oars or wind. His notebooks contain several studies of boats, water resistance, and mechanical transmission.
The concept was not a steamboat. Steam engines were developed centuries later, and Leonardo’s design depended on people turning the mechanism. It also should not be confused with a conventional galley, whose propulsion came mainly from banks of oars.
Leonardo’s paddle-boat studies illustrate his habit of treating transportation as a mechanical problem. He considered how rotary motion, gearing, and the shape of a hull could work together. The surviving drawings are engineering proposals, so they do not establish that a full-size Leonardo paddle boat was built or used successfully.