Leonardo da Vinci’s paddle boat design used two paddle wheels to move a boat through water.
The design appears in Leonardo’s studies of watercraft and mechanical power. Cranks and gears were intended to transfer the crew’s effort to paddle wheels mounted at the sides of the vessel. Turning the mechanism would push water backward and propel the boat forward.
The concept resembles later paddle-wheel boats, but Leonardo did not invent the general idea of paddles being used for propulsion. His contribution was a detailed Renaissance mechanism that applied gears and human power to a boat in a compact, organized form. The design was never documented as a completed Leonardo-built vessel.
This craft is different from a screw-propelled boat, whose underwater propeller rotates around a central shaft. It is also different from a gondola, which is moved by a manually operated oar. Leonardo’s paddle boat belongs to his broader interest in using machines to control motion on water.