Leonardo da Vinci designed a paddle boat propelled by rotating paddle wheels.
The concept used human power to turn mechanisms connected to paddles, which pushed against the water and drove the vessel forward. Leonardo explored this arrangement as an alternative to oars and sails, especially for controlled movement on rivers and other relatively calm waterways.
The design was not a steam-powered paddle steamer. Steam engines and practical steamboats appeared centuries later. Leonardo’s paddle boat belongs to an earlier tradition of experimenting with mechanical propulsion, and his drawings show how gears, cranks, and paddle wheels could convert rotary motion into movement through water.