What type of boat did Leonardo da Vinci design with a paddle wheel for propulsion?

Leonardo da Vinci designed a paddle-wheel boat propelled by rotating wheels rather than sails or oars.

His sketches show paddle wheels mounted along the sides of a boat and connected to a mechanical drive system. Turning the wheels would push against the water and move the vessel forward.

Leonardo investigated paddle propulsion as part of his studies of waterways and machines. The idea was not a steamship: the power would have come from people operating cranks or other mechanical mechanisms. Steam-powered paddle boats appeared centuries later.

Paddle wheels became important in later river and lake transport, especially during the nineteenth century. Leonardo’s design is therefore best understood as an early mechanical-propulsion proposal, not as a finished powered vessel.