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

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

In the early sixteenth century, Leonardo drew a system for underwater exploration that included a sealed suit, a mask, and tubes leading to the surface. The tubes were intended to carry air to the diver, while a cork structure helped keep them above water. His notes also included provisions for underwater movement and a container for collecting urine.

The design was associated with military and engineering ideas, including the possibility of secretly approaching enemy ships. It was a concept rather than a documented practical diving outfit. The materials and air-delivery arrangement would have created serious problems with pressure, buoyancy, and ventilation.

Leonardo’s proposal should not be confused with modern scuba equipment. Scuba uses compressed gas carried by the diver, whereas Leonardo’s system depended on air supplied from the surface. It also predates the diving suits and helmets developed during the eighteenth and nineteenth centuries.