Leonardo da Vinci studied a paddle wheel as a way to propel a boat.
A paddle wheel moves a vessel by pushing water backward with broad blades, producing forward thrust. Leonardo’s sketches explored mechanical systems that could drive paddles from the vessel, reducing dependence on rows of oarsmen and making propulsion more systematic.
The idea is sometimes mistaken for a screw propeller because both are marine propulsion devices. A paddle wheel turns in or above the water with visible blades, whereas a screw propeller uses rotating helical blades beneath the hull. Leonardo’s studies belong to the long history of experimental boat machinery.
His watercraft designs were not all practical prototypes, and surviving drawings do not establish that he built a successful powered boat. They do show his close attention to gearing, motion, and fluid resistance.