Leonardo da Vinci designed underwater breathing equipment commonly described as a diving suit.
His notes show a diver wearing a protective suit connected to the surface by breathing tubes. The equipment included a mask and a system intended to supply air while the diver worked underwater. Leonardo also considered ways to manage buoyancy and bodily waste during a prolonged dive.
The design was associated with military and engineering projects, including the possibility of underwater operations against enemy ships. Leonardo worried that such technology could be misused, and accounts of his work often connect its secrecy to that concern. There is no reliable evidence that he built or tested the complete suit in the fifteenth century.
Leonardo’s concept should not be confused with modern scuba gear. Scuba equipment carries compressed gas underwater, whereas his proposal depended on air supplied through tubes from above the surface. The design nevertheless anticipated several features of later diving equipment.