Leonardo da Vinci studied a paddle wheel as a propulsion device for boats.
A paddle wheel moves a vessel by pushing water backward with broad blades or paddles. Leonardo’s notebooks contain designs for boats using rotating paddle mechanisms, driven through cranks, gears, or other mechanical linkages. The aim was to produce propulsion more efficiently or with fewer crew members than ordinary rowing.
Leonardo’s boat studies were part of a wider interest in waterways, canals, hydraulic engineering, and mechanical power. His designs were not the same as later steam-powered paddle-wheel ships, which used engines to turn their wheels. Leonardo was exploring the mechanism centuries before practical steam navigation.
A paddle wheel also differs from a screw propeller. The wheel acts at or near the water’s surface, while a propeller uses rotating blades submerged in water. Leonardo’s sketches therefore belong to the history of paddle propulsion rather than modern propeller ships.