On Sun, 20 Nov 2005 23:00:22 -0400, Terry Spragg wrote:

Brian Whatcott wrote:
All you need is an exhalation valve at the mask, and an iron lung to
enable you to suck air below about 4 feet. Try it, just suck in
through the mouth using a harden hose and exhale through your nose.
Good luck.

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?)

Or a powered snorkel pump on a float on the surface, know as a
hooka, and some dive weights.

that works, I've done that..

--
http://maps.google.com/maps?q=irelan...244,0.0822&t=k

Iain Hibbert wrote:
On Sun, 20 Nov 2005 23:00:22 -0400, Terry Spragg wrote:


Brian Whatcott wrote:
All you need is an exhalation valve at the mask, and an iron lung to
enable you to suck air below about 4 feet. Try it, just suck in
through the mouth using a harden hose and exhale through your nose.
Good luck.


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.


Or a powered snorkel pump on a float on the surface, know as a
hooka, and some dive weights.


that works, I've done that..

Well, then just sit on the bottom at the shallow end of the pool so
that your head is about a foot under water, your lungs about 2 feet
under. Then take a standard, one foot long snorkeling snorkel in your
mouth upside down, so that you can point it to the surface.
Try to inhale.
This won't suck up your lungs, but give you a good idea of the
principle.
That's why snorkels are so short, duh.
While you are in the pool take a thin garden hose to the deep end and
see at what pressure it collapses. Don't try to inhale through it, you
would just exhale quicker and deeper than you wanted.

"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. 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.

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.

JimB

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

"Gary" wrote in message
news:tS%gf.578681$oW2.415490@pd7tw1no...
News f2s wrote:

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.

Gary, you also get squeezed if you hold your breath, though
slightly less.

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.

We *were* talking about using a breathing pipe to inhale
uncompressed air. I've tried this, and found a technique that
allows me to breathe under a shallow hull, using a long pipe, just
a little deeper than with a snorkel. I don't recommend it. And
yes, I do have a tough rib cage. And yes, I hold my breath to go
temporarily deeper, and I do the breathing cycle at the shallowest
depth possible, and I usually work upside down - hands at 4ft and
lungs at 2ft. All of which makes it possible to work around a prop
wrapped with a fishing net without getting the tanks out.

However, there are serious hazards in playing this game without a
great deal of care, practice and preparation. Since you obviously
have enough under water experience to make rather patronising
comments, I'm sure you appreciate this.

JimB

"News f2s" wrote in message
...

"Gary" wrote in message
news:ixPgf.570915$oW2.460791@pd7tw1no...
Iain Hibbert wrote:

Snip

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.

JimB


air breathing diving of any sort is full of traps for the unwary.

Reminds of the article in one of the recent Northwest Yachting magazinea
describing the fellow living on his Hinckley?/Hallber-Rasey? 46 in Costa
Rica. He became enamoured of free diving. Unfortunately one time he needed
to come up there was a big power boat overhead. He drowned. Seems like a
dumb way to lose a beautifull boat/life.

"Gordon Wedman" wrote:


"News f2s" wrote in message
...

"Gary" wrote in message
news:ixPgf.570915$oW2.460791@pd7tw1no...
Iain Hibbert wrote:

Snip

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.

JimB

air breathing diving of any sort is full of traps for the unwary.

Reminds of the article in one of the recent Northwest Yachting magazinea
describing the fellow living on his Hinckley?/Hallber-Rasey? 46 in Costa
Rica. He became enamoured of free diving. Unfortunately one time he needed
to come up there was a big power boat overhead. He drowned. Seems like a
dumb way to lose a beautifull boat/life.

Some people can do quite well free-diving. My SIL does this for the
lobster season in FL, and can stay down for a considerable time. Even
I can dive on the prop and do some work on it if I wear fins. It is
not that hard if you practice and it makes a reasonable workout. The
only time I can't do too much is if the water is cold - I can't stay
in too long in cold water, and if I wear a wet suit, I am too buoyant
to stay down.

It sounds to me like the guy in Costa Rica didn't have a dive flag or
take appropriate safety measures - like having someone watching.


grandma Rosalie

Rosalie B. wrote:

Some people can do quite well free-diving. My SIL does this for the
lobster season in FL, and can stay down for a considerable time. Even
I can dive on the prop and do some work on it if I wear fins. It is
not that hard if you practice and it makes a reasonable workout. The
only time I can't do too much is if the water is cold - I can't stay
in too long in cold water, and if I wear a wet suit, I am too buoyant
to stay down.

It sounds to me like the guy in Costa Rica didn't have a dive flag or
take appropriate safety measures - like having someone watching.

It was reported in Lat 38's Electronic Latitude that he was
the victim of shallow water blackout, not having a boat
above him.

Shallow water blackout occurs when you hyperventilate too
much before a freedive, and then when down, you run out of
O2. Your body uses increasing levels of CO2 to tell you
when to breathe, and hyperventilating reduces blood CO2. So
you don't get the urge to breathe, and pass out underwater.

I've come close a few times (black spots as I come up).
Now I only ever hyperventilate 3 deep breaths before a dive.
Diving with a buddy close by might save you, but by the
time they notice a problem you might be 20' deep and sinking...

It reduces my bottom time slightly but I feel a lot safer

Evan Gatehouse

"Evan Gatehouse" wrote in message
...

Shallow water blackout occurs when you hyperventilate too much
before a freedive, and then when down, you run out of O2. Your
body uses increasing levels of CO2 to tell you when to breathe,
and hyperventilating reduces blood CO2. So you don't get the
urge to breathe, and pass out underwater.

Thanks for that one Evan. I wasn't aware. I've had a dizzy spell
or two, and hadn't thought through the cause too carefully.

JimB