The main problem overcome by scuba equipment is giving a diver air at a pressure that matches the water pressure of his surroundings and can be breathed. This is why you cannot run a hose to the surface and breathe through it because after 3 or 4 feet, the water pressure is high enough that is prevents you from breathing air at surface pressure.
The Air Cylinder
Air cylinders are bottles made of aluminum or steel, and they are designed to hold a large quantity of compressed air under high pressure.
First Stage Regulator
The first stage of the regulator is a device that is clamped onto the air cylinder and uses valves to control the release of high pressure air from the cylinder so it is reduced to a lower and intermediate pressure when released into the scuba equipment's system of hoses.
Second Stage Regulator
The second stage of the regulator is the breathing mouthpiece, which uses valves to further reduce the air pressure to match the surrounding water pressure so it can be breathed safely.
One hose from the first stage of the regulator leads to a console, which has analog gauges or a dive computer attached. That connect allows a meter to monitor pressure inside the air cylinder and thus provide a reading on the amount of air remaining in it.
Another hose from the first stage connects to the diver's buoyancy control device, or BCD. This is a vest with air bladders so the hose allows a diver to use air from the cylinder to change his buoyancy, either for "hovering" underwater or floating on the surface.
Article Written By Edwin Thomas
Edwin Thomas has been writing since 1997. His work has appeared in various online publications, including The Black Table, Proboxing-Fans and others. A travel blogger, editor and writer, Thomas has traveled from Argentina to Vietnam in pursuit of stories. He holds a Master of Arts in international affairs from American University.