Leonardo da Vinci designed a paddle boat with side-mounted paddle wheels for propulsion.
The design used rotating wheels fitted with paddles to push against the water. Turning the wheels would drive the boat forward, offering an alternative to ordinary oars. Leonardo explored the concept while studying waterways, transport, and mechanical power, and his drawings show how gears could connect an operator’s motion to the paddle wheels.
The design was not a modern motorboat. It depended on human or mechanical power and was part of Leonardo’s experimental approach to water transport. Paddle propulsion had also been considered and used in other cultures and periods, so Leonardo should be credited with a Renaissance design study rather than the invention of every paddle-driven vessel.
A paddle boat differs from a propeller-driven boat because its paddles act visibly against the water at the sides or rear. That makes the mechanism easy to understand but often less efficient than a submerged screw propeller.