What boat design did Leonardo da Vinci equip with paddle wheels?

Leonardo da Vinci designed a paddle boat propelled by paddle wheels.

His sketches show a vessel whose rotating paddles would push against water and drive the boat forward. The mechanism was intended to convert the motion of a crank into propulsion, avoiding dependence on wind or ordinary rowing.

Leonardo studied boats, canals, rivers, and hydraulic machines throughout his career. A mechanically powered boat could have been useful for transport or military movement, especially on calm inland waterways. However, his design remained a concept and did not launch a sustained powered-boat industry.

The invention should not be confused with a propeller-driven vessel. Paddle wheels push water with broad blades mounted around a wheel, while a propeller uses rotating blades beneath or behind the hull. Steam-powered paddle boats became practical much later.