What kind of boat did Leonardo da Vinci design to move using paddle wheels?

Leonardo da Vinci designed a paddle boat intended to move using paddle wheels.

Paddle wheels propel a boat by pushing water backward with flat blades. Leonardo’s design placed mechanically driven paddles at the sides of the vessel, allowing it to move without depending entirely on wind or oars. The concept belonged to his wide-ranging studies of water transport and mechanical power.

Leonardo’s proposal was centuries ahead of the practical paddle steamers that became important in the 19th century. His boat did not have the efficient steam engines later used by commercial vessels, and there is no evidence that the design operated as a successful working craft.

A paddle boat is not the same as a submarine. Leonardo also explored underwater craft ideas, but a paddle-driven surface vessel is designed to travel on top of the water.