What Leonardo da Vinci boat invention used paddle wheels instead of oars?

Leonardo da Vinci’s boat invention that used paddle wheels instead of oars was the paddle boat.

Leonardo sketched a vessel propelled by paddle wheels, with mechanical linkages transferring motion from operators to the wheels. The arrangement was intended to make a boat move without relying on conventional rowing. His studies of water movement and mechanical transmission helped him explore how rotary motion could be converted into propulsion.

The proposal belongs to Leonardo’s broader work on waterways, canals, and machines driven by human or natural power. A paddle wheel can push water backward and produce forward thrust, but the design’s practical performance would have depended on the strength of its gearing, the resistance of the hull, and the number of operators.

Leonardo did not invent the general idea of using paddles to move a boat; ancient and medieval cultures had used related devices. His importance lies in the detailed Renaissance engineering treatment of the mechanism. The concept also predates powered steamboats by centuries.