Leonardo da Vinci designed a paddle boat with two large paddle wheels for river travel.
His notebooks contain designs for boats moved by paddle wheels rather than by oars alone. In the concept, mechanisms inside the hull transfer human effort to large wheels positioned at the sides. The paddles would push against the water and propel the craft forward.
This was a practical response to a familiar transportation problem: moving people or goods along waterways without relying entirely on wind or coordinated rowing. Leonardo’s studies examined gears, cranks, bearings, and other parts needed to turn a power source into motion. The surviving drawings are evidence of mechanical planning, not proof that this exact boat was completed.
The design should not be confused with a screw-propelled steamer, which uses a propeller below the water. Leonardo’s paddle-wheel idea belongs to the broader history of mechanically propelled boats and resembles later paddle steamers in its basic method of pushing water backward.