Leonardo da Vinci designed a paddle-wheel device intended to propel a vessel through water using rotating paddles.
The concept transferred circular motion from a mechanical system to broad surfaces that pushed against the water. In principle, each paddle would produce thrust as it entered and moved through the water, allowing a vessel to advance without relying solely on conventional oars. Leonardo included watercraft and naval mechanisms among the engineering subjects he studied.
Leonardo’s paddle-wheel sketches were proposals, not evidence that he built a successful powered ship. Renaissance engineers frequently drew machines whose practical performance had not yet been tested, and surviving drawings may omit construction details. The idea is therefore best understood as an early mechanical propulsion concept rather than a modern powered boat.
Paddle wheels later became important in riverboats and steamboats, especially in the eighteenth and nineteenth centuries. Leonardo’s design is sometimes mixed up with his studies of screw propulsion, but a paddle wheel generates thrust with projecting blades or paddles rotating at the side or rear of a vessel.