Oh, WHY do I read Basic Scuba Discussions? It BUGS me at times and then I just CAN'T keep my mouth shut. So, here we go again, this will be a LONG one...
OK, what follows is the "alternative" view to Narcosis. A word of caution. All these nice folks responding to this topic have undoubtedly convinced most people reading that you ARE narced ANYTIME you might feel "unusual" below 50 FT. As a result, you probably now believe it and are anticipating such effects when diving. Please keep believing it because I don't want to try and change your mind!
That said, and since some posts in this thread have compared narcosis and drinking, let's first talk about that. I go into a bar. Let's say I'm an occasional social drinker. Its been a rough day on ScubaBoard, the DIR folks have been driving me crazy (JUST JOKING !!!). I have 5 beers over one hour then leave. A few minutes later I swerve on the road and get pulled by a passing cop. I pass only a few of the sobriety tests the officer gives me and blow a .15 on the meter. I think everyone reading this would probably agree that Id be just as drunk regardless of if the bartender said dont worry about it, youll be fine you can handle it, or if I had attended a MADD meeting earlier in the evening warning about the tragedies and consequences of drunk driving.
The point is, my ATTITUDE about drinking wouldn't have affected the outcome.
Now, let's change the scenario. I'm a new diver. I don't read ScubaBoard (GASP!). My instructor tells me that Narcosis is a problem, but one that can be managed. He discusses the warning signs, how to "prepare" for narcosis during a deeper dive, what to be careful with. My friend, who's taking a class at another shop, does the "home reading" course and glosses over narcosis. He reads ScubaBoard instead and gets LOTS of opinions. Hes told that "diving deep on air is BAD, AVOID it at ALL costs because you WILL get narced and you could DIE!" During his class, the instructor makes an offhand remark that "everyone diving deeper than 80 FT gets narced to some degree." My buddy hears it and believes it.
A few months pass. My friend and I do several dives, between 30 and 60 FT. We decide to do a boat dive on a wreck, to a max depth of 110 FT. Both of us dive air. When we get to the deepest bottom, my friend acts "weird." He doesn't respond to hand signals and is in obvious danger. He's narced. I get control of him, help him to the anchor line and we head to the surface. Back on the boat, he can't remember any particulars of the dive or what happened. On the other hand, I remember everything including how I "rescued" him off the bottom, what depth we were at and what our BT was when the incident happened.
So what was the difference between my friend and I? For argument's sake let's say both of us are about of equal size and weight. 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.
This "effect" is called anticipated behavior modeling and was observed and tested with divers as test subjects back in 1965 by George Milner and Tom Mount (the same guy who became the head of IANTD). For a summary of the study that others have asked for in this thread,
click here. DAN also discusses this "issue" in terms of decreasing diver "anxiety." For that article,
click here. The key finding to take away from both these papers is that purely on the basis of knowledge, education and ATTITUDE, one can be better prepared for the effects of narcosis and
perform better in the actual environment. Diver experience alone, in the Mount-Milner study,
was NOT a factor that contributed to performance differences between the groups. Please NOTE that last observation.
So, in
my opinion, there IS a BIG difference between N2 and alcohol.
No matter how much you know about beer and drinking, if you drink 5 beers you can still get drunk and still become impaired. But, its NOT the same for diving. All things equal between two divers, if one diver has been taught about the effects of narcosis, is prepared for it and has the right ATTITUDE, 5 ATM of pressure won't always impair this diver, even when the diver has minimal experience. BUT, conversely, if another diver was told of the "negative effect" of narcosis and was also told that he or she "couldn't prevent it," that diver WOULD most likely be impaired. This effect, identified as anticipated behavior modeling, is NOT something that occurs when one consumes alcohol.
So what am I trying to say here? Well, it's not always the depth that contributes to the "problem" of narcosis. Instead, it's YOUR degree of diving "comfort," the environmental conditions and the task loading that you experience underwater. When you are "used" to a routine, you can prepare yourself mentally for what will PROBABLY happen (even train for it). BUT, start adding "new" stuff (especially a new dive site, new equipment, unexpected circumstances, etc., i.e., less "known" stuff) and unintended effects will occur. You lose the "focus" you have adjusted to and become susceptible to narcosis.
Just read most of the responses to this thread about when and how people experience narcosis and you can see that. This is why narcosis might occur one time but not another to the same diver. Focus is the reason why NASA trains astronauts again and again and AGAIN in the NBL prior to a mission. They make stuff "routine" in order to reduce cognitive stress. This prevents mistakes and issues from becoming PROBLEMS.
I hope my point to all of this is obvious. It's NOT the gas or depth that always matters. It's the TRAINING and EXPERIENCE.
If you are "routinely getting narced" at any depth, PLEASE ask WHY it's happening and re-examine the circumstances that lead up to it. I think it's unfortunate that diver education has become so "hands off" these days and quarries seem to be acceptable for any type of certification dive.
Just my thoughts...
