How to ensure N2 narcosis?

[Rhone Man]

If you want to feel narcosis, substitute argon for nitrogen in the mix (while obviously keeping the same oxygen content in the breathing gas). It's 2.3 times more narcotic than nitrogen. :shocked2: That should get you good and narced.

I have always thought this would be a safer way to teach narcosis management, but nobody ever takes me seriously.

Controlled experiment? Do some math and dexterity tests. Time on the surface and have buddy time you at the bottom.

This was really brought home to me when I was doing some deep dives and trying to mentally convert PSI into Bar. Very easy at the surface. Much, much harder at 130 feet.

 

[Thalassamania]

We used to call nitrogen rich mixes NARTOX, they were used in shallow habitats to lower ppO2 exposure.

 

[reo]

Thanks, Deefstes, for starting this thread. Thanks Walter & TSandM for your responses. I remember discussing Narcosis with my instructor when I did my AOW, but that was several years ago. At the time, I didn't give it much thought, because I believed most of my dives would be 65 feet or less. Most of my dives then were in the Boynton Beach/West Palm Beach area.

After I moved to the Seattle area, I've been on many dives deeper than 70 feet. Like others have said, I didn't feel any different. In the future, I'll be more aware that I am probably narced at those depths, and be a little more cautious.

Ron

 

[mikemill]

Solve pi to 10,000 places. That should keep you occupied for awhile. Then solve e after that.

And if you finish those, I'll have you do an ANOVA analysis on a data set spanning 20 years of economic data.

What if I just write the code to do that at depth?

Oh and I said math not statistics

 

[JanK]

My instructor had me doing a simple, but effective test. He had printed out numbers from 1 to 30 arranged randomly in a grid of 5x6 numbers (and had laminated the paper). I had to point out the numbers in increasing order.

On the shore it took me just under a minute, at 30 metres almost two minutes. And somewhere around a minute mark I started giggling when I realised how narced I was, even though there were absolutely no other indications that the situation was as bad. Quite an enlightening experience.

And the beauty of this test is that remembering such a sequence is something humans generally suck at (chimps are much better than humans at this), so you can actually use the same test more than once.

 

[Blackwood]

I'm not a big fan of math and writing 'tests', and to me the problem with narcosis isn't that I lose dexterity (fixed by slowing down). The problem is that it destroys multi-tasking.

Go down and try to handle multiple tasks. Odds are you'll break sooner than you would in the shallows.

 

[gcbryan]

I think the best suggestions are those to try to solve an unexpected but common underwater problem (not math) and see what your reaction time and abilities are like.

I know that when I'm deeper on air and need my buddy to assist me with something that the correct solution isn't going to occur right away. I'll have to explain the situation before they'll get it.

That's the best (or a good way) to experience narcosis and that's through watching your buddy try to figure out what you're trying to say.

I disagree that every incident attributed to narcosis is narcosis related however (especially the more dramatic shallow depth examples).

For instance, I've gotten into the water (only once) with my tank not fully turned on, I've almost gotten into the water a time or two with it turned completely off. This wasn't because I was narced. It was because I'm human.

We're human at 100 fsw as well so every mistake isn't narcosis related.

 

[TSandM]

One of the weirdest experiences of narcosis I've had was in the Red Sea. I did a dive on a wreck on 32%. Max depth was 100 fsw. I looked around the wreck and thought it was pretty boring, because there was no color on it -- it was all gray. We swam off into the blue water after a hammerhead shark and I didn't mind leaving it behind.

We did the same wreck the next day to a much deeper depth on trimix. To my amazement, the whole wreck was covered with soft corals and sponges and tunicates in an absolute riot of colors. I thoroughly enjoyed it.

The last dive was a traverse, that involved passing that same wreck again, and I was again on 32%. I looked around with dull curiosity -- the whole wreck was gray again. Although these dives were not all done at the same time of day, the water and weather were clear, and I don't think lighting was the difference (besides which, I bring the sun down with me anyway).

 

[gcbryan]

One of the weirdest experiences of narcosis I've had was in the Red Sea. I did a dive on a wreck on 32%. Max depth was 100 fsw. I looked around the wreck and thought it was pretty boring, because there was no color on it -- it was all gray. We swam off into the blue water after a hammerhead shark and I didn't mind leaving it behind.

We did the same wreck the next day to a much deeper depth on trimix. To my amazement, the whole wreck was covered with soft corals and sponges and tunicates in an absolute riot of colors. I thoroughly enjoyed it.

The last dive was a traverse, that involved passing that same wreck again, and I was again on 32%. I looked around with dull curiosity -- the whole wreck was gray again. Although these dives were not all done at the same time of day, the water and weather were clear, and I don't think lighting was the difference (besides which, I bring the sun down with me anyway).

You're saying that when you put a light on colorful sponge, coral and tunicates it doesn't bring out the color unless your on a helium mix?

 

[TSandM]

I'm saying that for me, at 100 feet, I put my light on things on Nitrox and they either appeared gray to me or I remembered them later as being gray. In the same area of the wreck, on 35% helium, I saw colors. Something in my brain worked differently on the helium dive. I was really quite amazed by it.