What type of ship did Leonardo da Vinci propose with paddle wheels driven by human power?

Leonardo da Vinci proposed a paddle-wheel boat driven by human power.

His sketches show boats equipped with rotating paddle wheels and mechanical linkages. The paddles would push against the water to produce forward thrust, while people turned or operated the mechanism. This approach aimed to reduce dependence on wind and make a vessel’s movement more controllable on calm water.

The idea was not a steamship. Steam engines and practical powered paddle steamers appeared centuries later, after developments in boilers, engines and industrial manufacturing. Leonardo’s design was a human-powered mechanical boat, closer to an experimental rowing machine than to a modern powered vessel.

Paddle wheels were later used successfully on riverboats and ships, but Leonardo’s particular proposal did not become a documented working commercial craft. His drawings are important because they show him treating propulsion as an engineering problem involving energy transmission, water resistance and coordinated moving parts.