Gee, if it is not really compressed air, why do they need a COMPRESSOR to get it down to them?
Surface Supplied...people, people!!
- Thread starter teknitroxdiver
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Wow... I guess things have really changed over the years.
It must be that global warming that has changed the properties of water so that it is easier to get bent now...
It must be that global warming that has changed the properties of water so that it is easier to get bent now...
I
idocsteve
Guest
When you are breathing at depth from a tank on your back, you are not actually breathing compressed aiir. You are breathing air that -was- compressed, but by the time it flows to your mouth from your regulator, it is no longer compressed...right? So it's the same as with surface supplied air...it comes out of the reg the same way. Its the fact that you are breathing at depth and under pressure that can cause the bends, and this can occur with scuba or snuba...at least that's how I would explain it to the ignorant ones.
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It depends how long their hose is. The NDL for 20' is a little over 5.5 hours.
Terry
Terry
teknitroxdiver:
idocsteve:
At depth, everything is compressed.
The pressure of the water above you compresses the air. Granted, the air is not compressed as much as it was in the tank, but it is compressed when you breathe it.
If you want to test this, fill up a 2 liter bottle with air in 90 feet of water and take it back up to the surface.
I
idocsteve
Guest
Nomad:
You are of course, correct. I think I ate too much turkey again. It's supposedly got a chemical that makes you drowsy and causes you to post inaccurate facts on scubaboard.
OP
teknitroxdiver
Contributor
True. These guys were talking the 60'+ range, though.Web Monkey:
miketsp
Contributor
Nomad:
Well if you take into account that dive tables 20 years ago were much more liberal than nowadays and cylinder pressures tended to be a little lower it was very difficult to get a dive scenario where you could pass table limits on a single cylinder.
Of course the percentage of people actually getting bent was higher. But more people got bent diving within limits than nowadays.
Heffey
Contributor
Everything at the surface is also compressed using that interpretation.Nomad:
At the surface you are breathing ambient pressure and at 90ft you are also breathing ambient pressure.
It is the rapid change in depth or altitude that causes the problems.
Yes it is - to 1ATA due to all the air above it before you hit space.Heffey:
At 90ft you are breathing gas at just under 4ATA - that's a lot more compressed than at the surface!Heffey:
Sure it's still ambient pressure. It's just a lot MORE ambient pressure than 1ATA...ergo...it's compressed! 
And those problems are a direct result of the dissolved gas in your tissues expanding due to the change in pressure...i.e. becoming less compressed.Heffey:
C'mon! This is Basic Open Water Theory 101
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