Leonardo da Vinci designed a paddle boat propelled through water by rotating paddles.
His notes include boat mechanisms in which paddle wheels or paddle systems would push against the water. Mechanical power, transmitted through gears or cranks, would replace the continuous rowing effort normally supplied by a crew. The concept belongs to Leonardo’s broader interest in using machines to amplify human labor.
The design is not a steam-powered paddle steamer. Leonardo had no compact steam engine to drive it, and the proposed system relied on human or mechanical input. It is also different from a sailing ship, whose main propulsive force comes from wind acting on sails.
Leonardo studied water movement, boats, canals, and hydraulic machinery throughout his career. His paddle-boat drawings show how he connected observation of fluid resistance with practical transport. As with many of his inventions, the notebook design is more securely documented than any full-scale trial or completed vessel.