Leonardo da Vinci designed a paddle boat propelled by paddle wheels.
The concept used rotating wheels fitted with paddles to push against the water. Mechanical power turned the wheels, offering an alternative to propulsion by oars or sails. Leonardo explored the arrangement as part of his broader studies of water-lifting devices, canals, boats, and hydraulic engineering.
His paddle-boat design was a proposal rather than a documented working vessel. Reliable engines did not yet exist, so the machine depended on human or mechanical power. Later paddle steamers used the same basic hydrodynamic principle, but their propulsion came from steam engines developed centuries after Leonardo.
The design should not be confused with a galley, which is primarily propelled by banks of oars, or with a submarine, which operates below the water. Leonardo also designed other watercraft, including boats intended for different military and transport purposes.