Leonardo da Vinci designed a paddle wheel as a mechanical propulsion device for boats.
His drawings show rotating wheels fitted with broad blades or paddles that would push against the water. Turning the wheel converts rotary motion from a mechanism into forward movement, offering an alternative to rowing with separate oars.
Leonardo’s naval studies included boats, pumps, locks, and devices for moving through water. The paddle-wheel idea belongs to this broader engineering work, although his notebooks do not establish that the design became a successful working vessel.
A paddle wheel is not the same as a screw propeller. A paddle wheel has blades arranged around a rotating wheel and interacts visibly with the water’s surface. A screw propeller uses a helical blade arrangement and became dominant in later powered ships.