Aquatic & Hydraulic Ingenuity - Diving Equipment

Earlier inventors had developed designs to help people breathe underwater. In Leonardo's enhanced design, a watertight leather tunic is reinforced by armour to protect the air bag from being compressed in deep water. Flexible cane hoses, with leather joints reinforced by spirals of metal, drew in air from above the surface, and valves regulated the air intake. The hoses were supported by a floating cork, which served as a buoy.

Leonardo thought this diving suit would enable divers to repair the hulls of ships underwater or permit an army of divers to march underwater to attack the hulls of enemy ships undetected. The latter idea was proposed by Leonardo in Venice as a strategy to overcome the Turkish flotilla that had besieged the bay outside the city.