Nitrogen narcosis

[100days-a-year]

It cannot be stated clearly or often enough that some people are more impaired @ .79 pN2 than others are @ 3.95 pN2 and that it is even more subjective and variable than decompression theory.
I assume everyone is impaired to some degree but that most folks are fully capable of pulling off dives to rec limits.

 

[johndiver999]

That fish collector looked narced out of his gourd! Does he kick normally in shallow water?

 

[FL-Jack]

Could not have said it better myself, and especially relevant is the "breathing part"!

On another note, and make of it what you will, this from a 'test' Tom Mount and some associates performed back in tbe 80's with new divers from, IIRC, a unniversity dive club / courses in Miami. They used two separate groupings over a period of time and set them test to do during the dive/s. They found in the cases where the instructor told the group they would get severly narced at 30m / 100ft, the majority did and on the whole pergormed the test poorly. Of the other group that was told there would be some effect from narcossis but as long as they were aware of such they could ' handle' it, the majority did 'handle' it, and the majority could perform the tasks set. However, in the end, the standout best 'performer' was a person from the first group, so again goes to show one shoe does not fit all.

So a take-away from all that is never overlook the power of suggestion, especially those divers that are just repeating ancedotes of what they have heard, or expect will happen to them, at depth. But dont get me wrong, narcosis cerainly does exist, and has proven a killer, but if you read some of the preceeding posts, and the above quote, you should realise that there were plenty of exceptions to the 'rule'.

But if I had my choice between air and gas (trimix), well it would be gas every time of course

Oh, and to the videographer I 'offended' a few pages back, your are right, there is more to shooting u/w video than just press and play. I, personally, just found it less demanding than u/w still photgraphy is all.

I like the power of suggestion theory. The vast majority of divers are tense and on the verge of a panic attack even when they are acting super cool on the boat or talking a good game at the bar, IME. Add some narc stories and a bit of an unfamiliar action down deep and their mind might just go off the rails regardless of narcosis.

 

[FL-Jack]

That fish collector looked narced out of his gourd! Does he kick normally in shallow water?

lol yeah he kicked like that everywhere. These dudes were managing a bunch of containers with crazy lids and nabbing fish left and right even deeper. It was quite impressive. I never put a video together of it because I don't want to encourage anyone to do try something crazy as this. I do have some really cool footage.though.

 

[Bert van den Berg]

My experience with narcosis is that I didn't know I was narced. I didn't feel a thing but the "narc test" that the instructor made me do proved it beyond a doubt.

The test was first done on the surface before the dive. The instructor timed how long it took me to write my name backwards. My name is rather long 'Bert van den Berg'. When narced it took twice as long and I wrote the word 'ned' twice.

 

[boulderjohn]

My experience with narcosis is that I didn't know I was narced. I didn't feel a thing but the "narc test" that the instructor made me do proved it beyond a doubt.

The test was first done on the surface before the dive. The instructor timed how long it took me to write my name backwards. My name is rather long 'Bert van den Berg'. When narced it took twice as long and I wrote the word 'ned' twice.

The narc test, once a requirement for PADI AOW, was removed years ago because of the opposite phenomenon. In far too many cases (the majority for me, in fact), the student did better at depth than on the surface. It was thus delivering the message that narcosis was no big deal. Part of the problem, too, was that the maximum depth for the AOW deep dive was 100 feet, so the student was barely getting into narcosis range. The dive could even be done at 61 feet.

 

[Celt]

My experience with narcosis is that I didn't know I was narced. I didn't feel a thing but the "narc test" that the instructor made me do proved it beyond a doubt.

The test was first done on the surface before the dive. The instructor timed how long it took me to write my name backwards. My name is rather long 'Bert van den Berg'. When narced it took twice as long and I wrote the word 'ned' twice.

I wonder how did Bob Neven get on ?

 

[johndiver999]

I wonder how did Bob Neven get on ?

He always did find as long as he paddled to the dive site in a kayak.

 

[Storker]

Being impaired and being able to function while impaired are not the same thing.

And being impaired and recognizing that one is impaired are not the same thing.

A lot of people seem to think that they can drive just fine with 0.08 percent BAC in their system. I know from experience that I can't do my job properly at any BAC, even less at 0.02 (our current legal limit) or 0.05 (our old legal limit). But then my job requires me to think pretty sharply, and any impairment is easily detected.

Because I'm rather used to evaluate my own mental capacity, I can't think of one single time where I've been below 30m and haven't been stupider than usual.

Others who don't depend as much on being mentally on top during their day job might not recognize that they're stupider than usual.

 

[boulderjohn]

And being impaired and recognizing that one is impaired are not the same thing.

I have said in many a past narcosis post that one of the symptoms of narcosis is that it prevents you from realizing you have symptoms of narcosis.