Types
Modern scuba sets are of two types:
- open-circuit (examples are those invented in 1864 by Rouquayrol and Denayrouze, in 1926 by Yves le Prieur or the Aqua-Lung invented to extend duration with a demand regulator in 1942/43 by Jacques Yves Cousteau and Émile Gagnan). Here the diver breathes in from the equipment and all the exhaled gas goes to waste in the surrounding water. This type of equipment is relatively simple, making it cheaper and more reliable. The two-hose design originally used was the one designed by Cousteau and Gagnan. The single-hose design generally used today was invented in Australia by Ted Eldred. In Britain it for a long time was often called an "aqualung".
- closed-circuit/semi-closed circuit (also referred to as a rebreather). Here the diver breathes in from the set, and breathes back into the set, where the exhaled gas is processed to make it fit to breathe again. These existed before the open-circuit sets and are still used, but less so than open-circuit sets.
Both types of scuba provide a means of supplying air or other breathing gas, nearly always from a high pressure diving cylinder, and a harness to strap it to the diver's body. Most open-circuit scuba and some rebreathers have a demand regulator to control the supply of breathing gas. Some "semi-closed" rebreathers only have a constant-flow regulator, or occasionally a set of constant-flow regulators of various outputs.
Read more about this topic: Scuba Set
Famous quotes containing the word types:
“Our children evaluate themselves based on the opinions we have of them. When we use harsh words, biting comments, and a sarcastic tone of voice, we plant the seeds of self-doubt in their developing minds.... Children who receive a steady diet of these types of messages end up feeling powerless, inadequate, and unimportant. They start to believe that they are bad, and that they can never do enough.”
—Stephanie Martson (20th century)
“... there are two types of happiness and I have chosen that of the murderers. For I am happy. There was a time when I thought I had reached the limit of distress. Beyond that limit, there is a sterile and magnificent happiness.”
—Albert Camus (1913–1960)
“Our major universities are now stuck with an army of pedestrian, toadying careerists, Fifties types who wave around Sixties banners to conceal their record of ruthless, beaverlike tunneling to the top.”
—Camille Paglia (b. 1947)