How deep can u go?

[Brian1968]

OTOH, we breathe a liquid for months during our gestation when our lungs are too weak to breathe gas, it seems incongruent I know, but it is interesting.

I aint no doc....but i was under the impression we, as babies in the womb recieved oxygenated blood from our mothers through our umbilical cords...no lungs required ? hence the "slap on the ass"...lol

oleras

You're actually both right. Gas and nutrient exchange take place in the placenta and are transported to the baby by the umbilical cord.

Unborn babies do "practice breathe" the amniotic fluid in and out of their lungs. However no gas exhange takes place.

 

[RichLockyer]

The absolute physiological limit would be when the gas in your tank wouldn't even be enough to equalize the gas filled spaces in the body and you would be hurt. This is like deep, several kilometers.

At 6700ft your 3000psi AL80 would equalize with the ambient pressure and you would not be able to get a breath out of it.

Not exactly "several" kilometers... less than 2.

I have read that around 2000ft the gas density causes breathing to become a severe problem... like breathing liquid.

 

[teknitroxdiver]

The max depth you could possibly descend to would be quite great. It would be the depth at which your breathing gas (definitly NOT air) would be so thich due to pressure that you could not inhale it. Of course, you could use a respirator-type apparattus to breath, but that would not really be 'diving' per-say. If liquid-breathing was made useable, that depth could be extended potentially infinite.

Also, oxygen toxicity would become a problem, forcing mixes of about .1%O2/99.9% helium, xeon, neon, or other exotic gas.

The decompression time from one of these dives would be unbelievable.

You say, you'd be crazy to go that far down. Possibly, but with enough training and lots of experience, you could do it with a reasonable amount of 'safety'.

Don't try it.

Edit: More info added.

 

[Kim]

Wouldn't you need a new tank design? The starting pressure inside the tank at the surface would have to be massive for it to deliver anything at great depth - 200 or 300 bar just wouldn't cut it! Any tank that could be pressurized to lets say - 2000 bar - would have to weigh so much that you'd probably need a crane to drop the diver down and bring him back up.

 

[teknitroxdiver]

Yeah there's another post on page 4 that tells the max depth before ambient pressure would be equal to the tank pressure. So you would have to have extreme pressure, and extreme volume. Remember that the deeper you go, the more air you use with each breath.

 

[Jim Baldwin]

Forget about the Maximum Recommended Depth in scuba class.

Hal Watts owner of Forty Fathom Gotto in Ocala, Florida held the deep diving record for AIR on open circuit scuba at about 425 feet. This was done years ago and Watts had the ability to slow his breathing and heart rate.


With the advent of heliox and trimix and hypoxic blends (less than 21 percent) you can go extremely deep. There have been dives made in the 1,000 to 1,500 foot range and probably some deeper I haven't read about. The helium helps make the air less dense and helps to eliminate the narcosis.

It's then SIMPLY a matter of having enough gas to do an extremely long deco schedule to get back to the surface safely.

Jim Baldwin

 

[RichLockyer]

Forget about the Maximum Recommended Depth in scuba class.

Do you really want to take responsibility for offering this advice?

Hal Watts owner of Forty Fathom Gotto in Ocala, Florida held the deep diving record for AIR on open circuit scuba at about 425 feet. This was done years ago and Watts had the ability to slow his breathing and heart rate.

Slowing his heart rate and breathing rate had nothing to do with the relative safety of this dive.
This dive was stupid.
Jim, I strongly suggest that you take a nitrox class and study what can happen under high pressures of O2. People have died diving air to 250ft, and it wasn't decompression illness that killed them. Oxygen becomes more toxic as you go deeper, and the current accepted limit for the level of oxygen found in air is 218ft, absolute max, and it is not recommended to go beyond 185ft.

been dives made in the 1,000 to 1,500 foot range and probably some deeper I haven't read about.

Nope... The current world record is 1032ft for open-circuit SCUBA. Commercial divers go much deeper, but they are running surface supply, and often wearing 1ata suits.

The helium helps make the air less dense and helps to eliminate the narcosis.
It's then SIMPLY a matter of having enough gas to do an extremely long deco schedule to get back to the surface safely.

Again, not that simple.
At 400ft, you're down to a mixture of 10% O2 and 70% helium. Going deeper requires less O2 to avoid toxicity, and more helium to prevent narcosis from becoming debilitating. At 200ft, the PPN2 from air is pretty much debilitating.
The problem is that too much helium can bring on HPNS, which can manifest itself in ways ranging from "the shakes" to a full-on psychotic episode.

 

[Mako Mark]

i was under the impression we, as babies in the womb recieved oxygenated blood from our mothers through our umbilical cords...no lungs required ?


oleras

I anit no pediatr.... peodiatik..... baby doctor, but you have made a good observation, As far as I know, babies do this for breathing muscle excercize NOT oxygenation.

.

hence the "slap on the ass"...lol

oleras

dont slap my ass, and dont make me come up there and slap yours!

 

[sharkbaitDAN]

The deepest dives to date were to 69.5 ATA in the Golf chamber at Duke AFAIK. There were problems at depth with HPNS, though symptoms subsided after the dives. I think I remember hearing that the deco scedule was close to a month.

http://www.diversalertnetwork.org/medical/tour/5golf.asp

 

[MikeFerrara]

Slowing his heart rate and breathing rate had nothing to do with the relative safety of this dive.
This dive was stupid.
Jim, I strongly suggest that you take a nitrox class and study what can happen under high pressures of O2. People have died diving air to 250ft, and it wasn't decompression illness that killed them. Oxygen becomes more toxic as you go deeper, and the current accepted limit for the level of oxygen found in air is 218ft, absolute max, and it is not recommended to go beyond 185ft.

'First we should note that while Hal Watts has held deep air recors he was one of the first sport divers to use helium.

Also, while narcosis is no doubt a problem I've not heard of a deep air diver toxing. I have heard of some just falling asleep at depth. CO2? It seems the narcosis offers some help with oxtox.

I had the chance to as Mr. Watts about the deep air stuff and the seemingly obvious problem of PPO2. He pointed out that they are bounce divews with very little exertion. I think the lions share of his deep. I wouldn't do it these days but he was diving deep before any one was using helium.