Was I Narc'd?

[Walter]

We took similar classes and have identical experience. BUT, I was told that narcosis could be MANAGED and I believed it. My friend, on the other hand, learned that he would probably get narced no matter what he did and, while in class, his instructor more or less confirmed this. So, he got narced because he believed he would.

You make excellent points, but you seem to have glossed over one. You are both narced. You are dealing with narcosis better than your buddy, but you are both impaired. You are not impaired to the same degree, but you are still impaired. Can narcosis be managed, of that, I have no doubt. One critical element in that management is to recognize you are impaired even when you do not notice any symptoms. You seem to be saying you are nor narced because you can manage narcosis. You can't manage anything that isn't present. In order to manage narcosis, you have to be narced.

I would also submit that managing narcosis is more than simply believing you can manage it. Part of it is dive planning. Visualize your dive before you hit the water. Make important decisions when planning your dive. Stick to the dive plan. Don't make changes on the fly unless they are to a back up plan you thought about before the dive (What do I do if I encounter an OOA diver? etc.).

 

[TSandM]

But are you saying that if you had been on 30/30 the class would have gone smoothly and there would have been no problems? Or were there other factors (besides narcosis) that were more of a factor. For instance, given your hallucination incident..the narcotic level at 100 fsw hasn't changed since that dive...other factors have. Is it correct to primarily attribute that incidence to narcosis?

My questions are entirely different than arguing that narcosis doesn't exist or isn't a factor. I'm just wondering if the term isn't misused a bit.

I'm sure your scientific view of narcosis and mine are the same. Starts at descent, increases with depth, it's (I guess) linear. But the day to day changes aren't changes in the narcosis. They're changes in the person apart from the narcosis.

Well, there were two hallucination incidents. And no, the level of nitrogen at that depth hasn't changed. However, my comfort level in the water and in low viz HAS -- if I had to guess, I'd guess that an ineffective breathing pattern due to anxiety, and thus CO2 retention, played a significant role in those early events.

And it is an interesting question whether it is changes in the person. The studies on oxygen toxicity definitely show that the response of the central nervous system to a toxin can be extremely variable, even when the dose of the toxin is constant. It may well be that narcosis is similar; it may also be that there are days when one is generally sharper than other days (fatigue, other distractions, illness or other things may degrade one's coping abilities before one is ever wet).

I'm not arguing that narcosis is constant or reliable; I'm simply arguing that there is no threshold effect, and that the ability to cope with novel problems is reduced with increasing depth. The research supports that, as well as the idea that the impaired diver may be completely unaware of his impairment. I think that speaks strongly to the need to have one's diving skills very solid, and basic problem-solving strategies developed BEFORE doing a lot of deep diving, because well-trained responses are going to be much more available to the diver when he's dull than the mental processing to develop solutions de novo will be.

 

[gcbryan]

Well, there were two hallucination incidents. And no, the level of nitrogen at that depth hasn't changed. However, my comfort level in the water and in low viz HAS -- if I had to guess, I'd guess that an ineffective breathing pattern due to anxiety, and thus CO2 retention, played a significant role in those early events.

And it is an interesting question whether it is changes in the person. The studies on oxygen toxicity definitely show that the response of the central nervous system to a toxin can be extremely variable, even when the dose of the toxin is constant. It may well be that narcosis is similar; it may also be that there are days when one is generally sharper than other days (fatigue, other distractions, illness or other things may degrade one's coping abilities before one is ever wet).

I'm not arguing that narcosis is constant or reliable; I'm simply arguing that there is no threshold effect, and that the ability to cope with novel problems is reduced with increasing depth. The research supports that, as well as the idea that the impaired diver may be completely unaware of his impairment. I think that speaks strongly to the need to have one's diving skills very solid, and basic problem-solving strategies developed BEFORE doing a lot of deep diving, because well-trained responses are going to be much more available to the diver when he's dull than the mental processing to develop solutions de novo will be.

Granted that knowing what you intend to do before you get in the water is important. I'd actually argue that narcosis is fairly constant. It may be semantics but that's why I don't consider the non-constant (inconsistent) problems people run into as being primarily narcosis. It's a constant level of narcosis (for that depth) that is acting as a catalyst for other issues. Narcosis doesn't change...people do.

Now of course many events that happen underwater are primarily or entirely narcosis related...just not the ones where people are doing something for the first time and are very anxious about it.

If you or anyone else is more comfortable in the water now at a given depth and those problems don't happen it's because they weren't primarily narcosis problems in the first place. They were problems made worse by the same level of narcosis that is still there at that depth that now isn't causing those problems.

This is more in your area than mine but when an anesthesiologist is prepping someone for surgery aren't the calculations more about size and weight (and some variability) rather than about how comfortable the person is, how much rest they got the night before, how worried they are, etc?

It's fairly constant isn't it?

 

[Thalassamania]

... I'm simply arguing that there is no threshold effect, and that the ability to cope with novel problems is reduced with increasing depth.

I'd agree and point out that with increased experience, especially at depth, the number of novel problems that present themselves fall off exponentially and that second order skill of learning how to cope with the novel also grows; and, in some individuals, seems to approach shallow water performance.

 

[lowviz]

.........I'm just considering why diving needs to be so complex?...........

I assume that you mean complex with regard to equipment. Equipment complexity will tend to increase as you stray further from recreational limits. With practice it all gets very familiar.

Sooner or later, most divers find that a routine dive got complex with regard to task overloading, and this is what one needs to prepare for. Random chance will put you there someday. In this regard, any simple dive can turn on you and quickly become very complex. This is my 'take' on complexity, preparing for what is likely to happen given enough time. And as for narcosis, it is real for me and one of the most variable variables in the mix. Go deep enough and it is always perceptible (to me) in some form, very reassuring when I'm deep and it is mild. Actually, quite pleasant. Other times...