What kind of suit did Leonardo da Vinci design for people exploring underwater?

Leonardo da Vinci designed a diving suit for people exploring underwater.

His early-16th-century concept included a leather suit, a mask, and breathing tubes connected to a floating device at the surface. The design was associated with plans for underwater military operations, especially attacks on enemy ships.

Leonardo's proposal shows that he understood the need to provide a diver with air while keeping water out. It was not a modern scuba system: it lacked the compact tanks, regulators, and materials that make contemporary autonomous diving possible.

The suit is often confused with a spacesuit because both protect a person in a hostile environment. Leonardo's design, however, was specifically for underwater use and depended on an air supply from above.