Leonardo da Vinci designed a paddle boat intended to move through water without relying on sails.
His concept used paddles driven by a mechanical transmission. Turning the mechanism would make the paddles push against the water and propel the craft forward. Leonardo developed such ideas while investigating canals, river transport, and the conversion of human or mechanical effort into useful motion.
The design was not a steam-powered paddle steamer. Steam engines were developed centuries later, and Leonardo’s boat depended on manual or mechanical power. It is also not the same as a modern propeller boat, because paddles interact with the water through broad blades rather than a submerged screw propeller.
Leonardo’s watercraft studies show his interest in practical engineering as well as spectacle. He examined boats, locks, pumps, and canal systems, often seeking ways to reduce effort and improve transport. His surviving sketches are proposals, not evidence that the exact boat was built and successfully operated.