What device did Leonardo da Vinci design to let a person breathe underwater?

Leonardo da Vinci designed a diving suit to let a person breathe underwater.

His design, recorded in the Codex Atlanticus, used a leather suit connected to breathing tubes that reached above the water. The tubes were intended to be supported by a floating structure, keeping their openings above the surface.

The concept belongs to Leonardo’s studies of water, breathing, and military engineering around the early sixteenth century. It was not a modern scuba system: it had no compressed-air tank, regulator, or underwater pressure controls.

Leonardo’s suit is sometimes called a scuba suit, but that is a historical mix-up. Modern scuba equipment developed centuries later and depends on stored compressed gas. Leonardo’s proposal was an ingenious theoretical design rather than a documented working invention.