How does scuba diving equipment work

Lucky Oliverg2 is off on a scuba-diving holiday, and wants to know how the equipment he will use works.

Q. What does SCUBA stand for

A. The acronym stands for Self Contained Underwater Breathing Apparatus, because the divers carry their own supply of air.

Q. When was scuba diving invented

A. Although the first crude scuba apparatus was invented over 150 years ago, the most significant breakthrough came in 1943 when Commander Jacques-Yves Cousteau and Emile Gagnan introduced the Cousteau-GagnanAqua-Lung . The Aqua-Lung used cylinders of compressed air and was equipped with a demand regulator, which adjusted the air pressure automatically, and supplied air as the diver needed it.

Q. What equipment is involved in scuba diving today

A. There are two main pieces of equipment for scuba diving: a cylinder, called a scuba tank, and an air pressure regulator.

Q. How does the cylinder and regulator work

A. The cylinder, usually made of aluminium or steel, stores air at between 200 and 300 times atmospheric pressure and allows divers to carry air with them when diving.

The air pressure regulator has two jobs. Firstly, it reduces the pressurised air in the cylinder to a pressure slightly higher than the water pressure at the depth at which the diver is diving. This is done by the part of the regulator that is clamped onto the cylinder, called the first stage of the regulator.

Secondly, it provides us with air when we inhale. This is done by the part of the regulator that the diver puts in his or her mouth, called the second stage or demand valve of the regulator.

Q. What is stored in the cylinder

A. Generally, just normal air that has been compressed up to between 200 and 300 times atmospheric pressure.

Q. What happens to the exhaled air when scuba diving

A. When the diver exhales the air from his or her lungs it is released into the surrounding water, seen as a rush of rising bubbles.

Q. Is it scuba diving dangerous

A. Like any adventure sport, diving has certain risks and it is essential that everyone receives certified training before attempting a dive.