News f2s wrote:
"Gary" wrote in message
news:ixPgf.570915$oW2.460791@pd7tw1no...

Iain Hibbert wrote:


Good Luck indeed, because if you go too far you are liable to
have your
lungs being sucked up the hose is what I heard (not sure how
deep is too
deep, anybody?)

That's dumb. All that happens is the hose collapses from the
pressure. Nothing is going to push your lungs up the
hose.......duh.


What happens is that as you go deeper it becomes progressively
more difficult to breath in, because your lung pressure is at
atmospheric, whilst the water pressure is increasing at about half
a pound per square inch for each foot of depth.
Duh! Of course if the hose is reinforced and more rigid than your chest
walls the you could get squeezed if you are not smart enough to hold
your breath.
The 'squeeze' that
another poster has referred to. This limits me to a depth of about
4 - 5ft. Any deeper and I have a coughing fit after re-surfacing.
Apparently that's caused by bits of the lungs collapsing, and the
coughing is a reaction to the little subchambers unsticking again.
Nasty feeling.
The air needs to be pumped down at the ambient pressure of your lungs.
After a couple feet *most* people can't suck hard enough to get air.
You might be the exception.

That's another reason why I say - you don't do this without plenty
of previous practice in the swimming pool to check out the feeling
of all the things which may go wrong. Better just take that deep
breath . . . air breathing diving of any sort is full of traps for
the unwary.
Good idea, nobody ever drowned in a swimming pool.

JimB