What type of boat did Leonardo da Vinci design with a paddle wheel for shallow water?

Leonardo da Vinci designed a paddle-wheel boat for moving through water with rotating wheels.

The concept used paddle wheels turned by mechanical power, allowing the blades to push against the water and drive the vessel forward. Leonardo’s studies of waterways and machines led him to explore several forms of water transport, including vessels suited to canals and shallow environments. The design connected mechanical rotation with the practical problem of propulsion.

Leonardo’s paddle-wheel boat is distinct from the separate rotating-paddle propulsion study often associated with his notebooks. It is also not a steam-powered paddle steamer: Leonardo had no steam engine capable of powering such a vessel. His design remained a proposal, but paddle-wheel propulsion later became important in powered boats and ships.