the regulator. Now there are also the submersible pressure gauges, the air gauge here in the

U.S. measured is pounds per square inch or PSI and in the rest of the world it measures

it in Bar. A full tank, typically a full eighty cubic foot tank holds about three thousand

PSI of air. This little red zone right here is not like, you're out of air, it's just

a caution zone, it's kind of like the gas light on your car, letting you know, hey you

might want to think about starting to come up but you don't have to right away. Depending

on the depth you're at you could have anywhere from three to ten minutes of air, roughly.

The depth gauge up here monitors the pressure of the water and determines the depth. Most

depth gauges also have a little needle that you can turn to mark your maximum depth of

that dive so you can calculate how much nitrogen you absorb and things like that. Even though

the depth gauge goes up to two hundred feet the recreational diver limit with deep diver

training, at least with PADI, is one hundred thirty feet. Some regulator set-ups also include

computers where they're integrated or not integrated. Basically what integrated means

is that it would be attached here and instead of an air gauge, the computer would monitor

how much air. Most people or a lot of people have these but they can fail every now and

then, so you need to have a back up system usually just in case. So a lot of people prefer

the non integrated computer because then you have your analog air gauge which rarely ever

fails and then your computer which can calculate how much nitrogen you absorb and how long

you can stay down based upon the depths you are at, pretty easy to operate. Most of them

have a log, which you can go back through and look at past dives.