What was Leonardo da Vinci’s proposed underwater breathing device designed to let a diver use?

Leonardo da Vinci’s proposed underwater breathing device was designed to let a diver use a breathing tube.

Leonardo described a diving apparatus in the early sixteenth century, especially in notes associated with the Codex Atlanticus. The design included a mask connected to a pair of tubes that reached above the water. The tubes were supported by a floating structure and were intended to supply air to a diver below the surface.

His concept also included a bag for collecting urine, acknowledging that a diver might remain underwater for some time. Leonardo was concerned that the device could be used for secret military operations, such as approaching enemy ships, and he reportedly kept parts of the idea private.

The apparatus was not a modern scuba set. It relied on surface air and lacked a compressed-air cylinder, regulator, and reliable underwater pressure control. Leonardo’s design is important because it shows an early systematic attempt to solve the problem of breathing underwater.