Since man began sailing on the oceans, lakes and rivers of the world he had a dream of being able to go below the surface and not to have to come up for air. He practiced holding his breath but the longest he could accomplish this for was about 5 minutes and even this took quite a bit of effort. There is a story of an event in ancient Greece concerning a breath holding diver, his name was Scyllis or Scyllias and took place around 500 BC. Scyllis was captured by King Xerxes of Persia. He was taken aboard a ship. He stole a knife and jumped overboard. The Persians searched the water for him but couldn't find him anywhere, so they presumed him dead. That night he swam along cutting the moorings of all Xerxes's ships. He had used a hollow reed as a snorkel to he could stay underwater. When he finished he swam 9 miles back to the Greek fleet.

Roman idea for a diving helmet and suit
Air was pumped down to the helmet. You had no way of seeing.
Photo Source: NOAA

The great Leonardo da Vinci was one of the first people to design an Aqua-lung. It was comprised of a blatter filled with air that the diver would breathe from while he was under water. Pictures of this can be seen on any good da Vinci site. Leonardo was just too far ahead of his time and the Aqua-Lung would have to wait for several hundred more years.

When the 16 century came along so did diving bells. While these did not allow for individual freedom of movement under the waves they did for fill one requirement, the need for air so that a person could remain submerged. These first bells were just vehicles that trapped air as they submerged, there was no air supplied to them from the surface. The air pressure as the bell submerged trapped the air in the top of the bell. The diver would swim out of the bell and could return for air by sticking his head up into the portion of the bell that had no water in it. The air wouldn't last too long. But in the same century something else came along that allowed a lot more freedom. The diving suit was made of leather and had air pumped into them. A diver could go down to 60 feet in one of these suits. They were used in England and France.

About 1680. Physicist Giievanni Borelli attempts to make a helmet and carry a pump to fill it with air.
He might not be able to breathe but at least he could see where he was going.
Photo Source: NOAA

The diving suit was being steadily improved. Soon metal helmets were made for it. This allowed divers to go even deeper. By the first third of the 19th century divers were able to do meaningful salvage work in their diving suits.

Hard Hat Diver
Photo Source: Library of Congress

In France another visionary, Jules Verne, foresaw man traveling beneath the ocean in his famous book, "20,000 Leagues Under The Sea". Not only did this tale predict the modern submarine but also divers with self contained air supplies. The book was very popular and no doubt the ideas it contained were partially responsible for the Aqua-lung.

By the time the late 1800's arrived, Henry A. Fleuss had invented the first workable self-contained compressed oxygen diving gear. This allowed for longer dives of up to 25 feet. The 25 foot limit was caused by the fact that below 25 feet pure oxygen is toxic. This depth was exceeded but the people of the time were now aware of what was causing the problems for their divers. This was the first scuba gear. In 1924 the first helium-oxygen dives are made by the US Navy. In 1933 a larger tank with a regulator is invented by the French. The diver must open and close the valve when he wants air.

In the second world war the Italians used scuba with self contained mixtures to swim to British ships and plant explosives on them from midget subs. The real breakthrough comes when Jacques Cousteau and Emile Gagnan developed a regulator that allows divers to take a breath naturally, this all happens in 1943 and the unit is tested and looks like a modern day scuba outfit. The rest is history.

Modern Day Divers
Photo Source: US Department of the Interior