Deep Air - Here we go again....

[DCBC]

Some like the OP may have an inherit nitrogen narcosis tolerance but by no means should anyone base their own personal limits of deep air diving on someone elses limits and anyone that says they are not narced at 200ft or can deal with it are in denial.

I agree and would even go further in saying that if people deny that their performance has been affected at 50' they are in denial. We can pretend that divers will not dive deep enough for narcosis to be a problem, but we would be in denial. Training can make a difference.

 

[UCFKnightDiver]

I agree and would even go further in saying that if people deny that their performance has been affected at 50' they are in denial. We can pretend that divers will not dive deep enough for narcosis to be a problem, but we would be in denial. Training can make a difference.

Sorry, but I'm just not understanding this, from the several studies I've read regarding nitrogen narcosis, it has been stated that narcosis effects your ability to think and problem solve but has little effect on your motor skills. If this is the case, all that training does is help to engrain the motor skills that you would need for a regular dive to that depth. The problem I see, is what if something goes wrong and you have to think through the problem.... will you be able to solve it diving deep air?

It's always something you haven't thought of that gets you.

-Ryan

 

[DCBC]

...narcosis effects your ability to think and problem solve but has little effect on your motor skills. If this is the case, all that training does is help to engrain the motor skills that you would need for a regular dive to that depth. The problem I see, is what if something goes wrong and you have to think through the problem.... will you be able to solve it diving deep air?

Thanks Ryan, good question; you're right. Narcosis is something that is insidious in-that it starts to affect you before you are aware of it. If the diver remains unaware, its affect may continue to increase to a point where it's debilitating. If a diver hasn't experienced this before the complications caused can be fatal. Obviously people don't die of narcosis, but by their own actions under the effects of narcosis.

Part of the instructional process helps the diver understand and anticipate the effects of narcosis, thus becoming aware. This shouldn't be underestimated. Planning is simplified and exposure time is limited by design. Subsequent exposure helps the diver recognize how he is being affected, drills are practiced, etc. So the first advantage of deep air training is the early detection of narcosis. This is followed by the advantages of dive planning including the development of the proper mental attitude. Narcosis should never cause a problem to a serious degree, as if you are aware and start to get to the point of being seriously affected, you ascend before it's affects take hold.

If an increase in narcosis performance is present, it has been attributed to repetition of the required task, so training that addresses key areas may only increase performance if it is one that has been foreseen; as opposed to creative thinking. No one is able to think as creatively as they could on the surface and this presents an additional danger to the deep air diver.

I am not taking the position that diving Deep Air is totally safe; anymore than using a CCR or decompression diving is totally safe. None of these are.

When we undertake any of these activities, the level of risk increases. In each case, additional training and experience may mitigate the hazard. The aim is to make the risk manageable or at the least, acceptable to the participant.

Despite some of the comments made, I'm perfectly aware of the advantages of Helium having logged 4032 hours saturated one year. The simple fact remains that it's not available to everyone, everywhere. If there are people that don't have this problem, that's great. In reality, it's not that easy for everyone.

I also understand that people here dive for fun and games. If a dive requires too much risk from their perspective, they can go bowling instead. I cannot help but think that a "technical diver" lecturing me on risk is somewhat amusing.

 

[ucfdiver]

I cannot help but think that a "technical diver" lecturing me on risk is somewhat amusing.

Then why not go to a commercial diving forum? You clearly know everything, and it's becoming obvious that the rest of us aren't going to listen to your expertise.

 

[JeffG]

Then why not go to a commercial diving forum? You clearly know everything, and it's becoming obvious that the rest of us aren't going to listen to your expertise.

Because doing it this way makes him feel superior and the ego grows even more.

 

[nadwidny]

Because doing it this way makes him feel superior and the ego grows even more.

Pretty much describes everyone who posts a picture of themselves in a hardhat as their avatar. 'Cause that just makes us recreational types go weak in the knees with awe.

 

[JeffG]

Pretty much describes everyone who posts a picture of themselves in a hardhat as their avatar. 'Cause that just makes us recreational types go weak in the knees with awe.

I'm not even sure you need a high school diploma to be a commercial diver.

 

[nadwidny]

I'm not even sure you need a high school diploma to be a commercial diver.

(Well to be fair) - Or the premier of Alberta

 

[JeffG]

(Well to be fair) - Or the premier of Alberta

Lumping commercial divers in with politicians?


Now thats low.

 

[Sloth]

"There is no question that there is an individual susceptibility to the effects of nitrogen
narcosis. This may be due to individual accommodation or “learning to cope”
with a reduction in anxiety and recognition by the individual of his own signs and
symptoms. Thus highly trained and experienced deep divers may be able to function
much more effectively at depths which would incapacitate less experienced divers.
Such experienced deep divers will pace themselves, be slow and methodical and exert
extra effort and concentration to try to mitigate the narcosis compared to an
individual, for example, experiencing 300 fsw narcosis for the first time. However,
normal biological variability due to different individual physiological susceptibility, as
in alcohol, is also a factor."
Brauer R (1983). Acclimation to nitrogen narcosis.


“that by careful choice of highly intelligent young men in excellent condition, one can select individuals who can acclimate very adequately to conditions which others might be seriously incapacitated as a result of nitrogen narcosis."
Lambertsen CJ, Wright WB (1973). Multiday exposure of men to high nitrogen
pressure and increased airway resistance at natural expired oxygen tension:


"While all subjects can accommodate to 100 fsw compressed air only, some, but not all, can compensate for 200 fsw during extended sojourns."
Stringer J (1983). Euphoria at 200 ft.

What you seem to not want to acknowledge is that just like peoples tolerance of alcohol people have varying levels of nitrogen narcosis tolerance. YOU may be able to work up to preform a 200 ft dive on air but your dive student A may not be. Many studies show the amount of denial that people will display in the face of nitrogen narcosis. Student A may be fine on his deep dive to air and may state that he is not narced but one day when bad things start to happen on a deep dive on air he might learn really quickly how much of an impact nitrogen narcosis is really having.

People will continue to dive deep on air for all the reasons you listed as everyone has to make their own risk assessment but I feel you do your students a disservice but stating that nitrogen narcosis is something that can be trained around when so much literature says that just isnt true.