Studies for an underwater breathing apparatus
Drawing from the Codex Arundel, folio 25r, by Leonardo da Vinci, c. 1508
The British Library, London

The main concept of da Vinci's idea in these studies involves a diver clad in a leather suit, offering some protection from the underwater environment. A key feature is a glass helmet, a clear precursor to modern diving helmets, allowing the diver some underwater visibility. Two tubes, potentially constructed from reinforced cane, connect the diver's mouth to a floating bell bobbing on the water's surface. These tubes, according to some interpretations, may have incorporated one-way valves to facilitate easier breathing. The floating bell acts as a crucial element, trapping air that the diver can breathe underwater. Da Vinci's notes even delve into potential methods for replenishing this air supply, with ideas ranging from bellows operated from the surface to, more curiously, a urine collection system. However, the exact functionality of these proposed replenishment mechanisms remains unclear. The principle ideas embedded in this design laid the groundwork for the development of modern scuba gear centuries later.