Timeline of diving technology

The timeline of underwater diving technology is a chronological list of notable events in the history of the development of underwater diving equipment. With the partial exception of breath-hold diving, the development of underwater diving capacity, scope, and popularity, has been closely linked to available technology, and the physiological constraints of the underwater environment. Primary constraints are the provision of breathing gas to allow endurance beyond the limits of a single breath, safely decompressing from high underwater pressure to surface pressure, the ability to see clearly enough to effectively perform the task, and sufficient mobility to get to and from the workplace. Ancient Roman and Greek era.: There have been many instances of men swimming or diving for combat, but they always had to hold their breath, and had no diving equipment, except sometimes a hollow plant stem used as a snorkel. About 500 BC: (Information originally from Herodotus): During a naval campaign the Greek Scyllis was taken aboard ship as prisoner by the Persian King Xerxes I. When Scyllis learned that Xerxes was to attack a Greek flotilla, he seized a knife and jumped overboard. The Persians could not find him in the water and presumed he had drowned. Scyllis made his way among all the ships in Xerxes's fleet, cutting each ship loose from its moorings; he used a hollow reed as snorkel to remain unobserved. Then he swam nine miles (15 kilometers) to rejoin the Greeks off Cape Artemisium. The use of diving bells was recorded by the Greek philosopher Aristotle in the 4th century BC: "...they enable the divers to respire equally well by letting down a cauldron, for this does not fill with water, but retains the air, for it is forced straight down into the water." 1300 or earlier: Persian divers were using diving goggles with windows made of the polished outer layer of tortoiseshell. 15th century: Konrad Kyeser, illustrated his manual of military technology Bellifortis with a diving suit fitted with a hose to the surface.