Leonardo da Vinci designed a paddle boat using rotating paddle wheels instead of conventional oars.
His drawings show vessels propelled by paddle wheels turned through a system of gears and cranks. The arrangement aimed to convert the coordinated effort of people into continuous rotary motion, potentially making propulsion more efficient than handling separate oars. Leonardo explored several watercraft and naval mechanisms while studying movement through water.
The paddle boat was a concept, not a proven Renaissance commercial vessel. Leonardo’s surviving drawings do not establish that he built and tested a full-size craft. Later paddle boats used similar basic principles, but they also benefited from improved engines and more reliable mechanical systems.
This invention should not be confused with a submarine. Leonardo did study underwater devices, but a paddle boat is a surface vessel whose wheels push against water to create forward motion.