A scuba diver descends with a portable apparatus that provides him the gas mix he needs for breathing (compressed air, oxygen, helium-oxygen, nitrogen-helium-oxygen) with which he can stay under water for very long periods of time.

In contrast to the traditional diver who receives the respiratory gas mix from the surface through an “umbilical cord” and who is bound to stay on the bottom due to his heavy equipment, the modern scuba diver does not depend from a fixed surface platform and carries with him on his back the necessary gas in a cylinder and can move freely with the use of the fins.  

The scuba diver keeps his buoyancy under water and can control it as he pleases, thanks to a special jacket – also called BCD for ‘buoyancy control device’ – which he can inflate with the air of his cylinder or deflate.

SCUBA DIVING
The use of an autonomous respiratory system is used to stay for prolonged periods of time under water. We differentiate between recreational diving and technical/professional diving. The equipment of both categories include a regulator with an open circuit, which was invented under the name ‘Aqua-Lung’ by Jacques Cousteau, or the so called ‘Rebreather’ which is a respiratory system with a closed or semi-closed circuit.

HISTORY OF DIVING / SCUBA DIVING
The desire to go under water probably existed since the very origins of mankind: to look for food, objects or artefacts, to repair ships (or to sink them) or just to observe the under water realm. But as long as a system was not yet invented that made breathing under water possible, the dives were rather short and hectic. In the 16th century, diving bells were used in which the air supply was guaranteed by the surface. This method represented the first real system to stay under water for an unlimited period of time. Two of the main research developments accelerated in a fundamental way the exploration of the under water world: the scientific and the technological approach. The scientific developments were sped up by the works of the Frenchman Paul Bert and the Scotsman Scott Haldane. At the same time, technological progresses such as air pumps and regulators etc. made it possible for man to stay longer under water. Since the beginning of the seventies, when the international tourism started booming, also a recreational or touristic interest for scuba diving developed, to simply “visit” the under water environment. And today, thanks to the innovative and constantly lighter and more comfortable diving equipment with improved technology, scuba divers are completely autonomous and can move under water almost without effort. To move underwater, the diver can lately also employ diver propulsion vehicles or simply use the sea currents.