What did Leonardo da Vinci’s diving suit use to supply air underwater?

Leonardo da Vinci’s diving suit used breathing tubes to supply air underwater.

His design included a leather suit, a mask, and tubes extending above the water’s surface. The tubes were intended to let the diver breathe while exploring beneath the surface. Leonardo also sketched related equipment, including a bag that could help provide buoyancy or collect air, depending on the proposed arrangement.

The concept was part of his studies of military engineering and underwater operations. A diver equipped in this way might have approached enemy vessels or inspected structures below the waterline. Leonardo’s notes show that he understood several practical problems, including buoyancy, waterproofing, and the need to keep the breathing path clear.

This design should not be confused with modern scuba equipment. It had no compressed-air cylinder and could not provide an independent air supply far from the surface. Leonardo also did not build a proven working suit or conduct a documented underwater test. The surviving drawings demonstrate inventive thinking, but they do not establish that the system was safe or operational.