How to ensure N2 narcosis?

[Deefstes]

OK, I'm probably going to get crucified for this but let's risk it.

I can't claim to be a very experienced diver by any stretch of the imagination but I've done a fair number of 30m dives so far and have never knowingly suffered from N₂ narcosis. I've done two dives to 40m and haven't experienced it either but both of those have been very brief dips to 40m during an otherwise shallower dive.

It's not that I desperately want to get narced but I am curious to know how it manifests in me and I think it would be useful to be familiar with the symptoms. So it got me wondering, is there not perhaps a way to induce N₂ narcosis under controlled conditions?

One thought that came up would be to mix a special breathing gas that's like an anti-Nitrox so to speak. I did some math and concluded that you're not going to achieve much this way. In order for this mix not be hypoxic at sea level you can't drop the O₂ to anything lower than 16% right (maintaining a ppO₂ of 0.16 at the surface.

I then calculated that for a mix of 16/84 O₂/N₂ a dive to 20m would have an EAD of 21.9m or a dive to 30m would have an EAD of 32.5m. So obviously that mix would be senseless. I'm using the assumption that only N₂ is narcotic.

One thing is for sure, I don't want to be breathing funny gasses when I have 30m of water between me and the seagulls and I also don't want to be breathing hypoxic mixes, not even just as a bottom gas. The math might prove it to be safe but I still don't want to do it. I did continue my mental exercise though just our of curiosity.

Let's say we're using a mix of 5/95 O₂/N₂. You can't breathe this gas at anything shallower than 22m at which point your EAD would be 28.5m but if you wanted an EAD of 40m say, you'd have to dive to 31.6m. I guess this mix might do the trick but, like I said, I have no desire to dive a funny gas to 30m or to dive a hypoxic mix, and most certainly not both at the same time.

Has anyone else tried this? Have you come up with any other ideas to "invite" N₂ narcosis?

Finally, surely I must be narced at 30m, even if I don't feel it? Is there an easy check to confirm whether I'm narced or not?

 

[ScubaSteve]

Do you have a Chamber close by? I have no idea what their educational rides are limited to but it may be possible for an educational chamber ride to include this experience. It might be worth looking into.

 

[knowone]

They're your numbers. Drunks seem to have a resistance. Drunk drunks more so. Buy a chamber or go to the dentist, or the drug store.

 

[dannobee]

The classic way to judge narcosis is to take a dive slate with various math problems with you, then solve the problems at depth. Compare with similar math problems at the surface.

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.

 

[Walter]

I can't claim to be a very experienced diver by any stretch of the imagination but I've done a fair number of 30m dives so far and have never knowingly suffered from N2 narcosis.

OK, so you've been narced a fair number of times, but haven't been aware of it. You were narced on each and every one of those dives (as well as your shallower dives to a lesser degree). Like you, I rarely feel any effects of narcosis. Like everyone, I am narced at depth. Unlike you, I am aware that I'm narced every time I dive.

I am curious to know how it manifests in me and I think it would be useful to be familiar with the symptoms.

Symptoms include loss of fine dexterity (take a slate on your next deep dive and sign your name), loss of short term memory, lowered IQ, slowed reaction time, and fixation on ideas. We rarely feel any of these. There are other symptoms we do feel, but they are not always present. If you want to feel narcosis, keep diving deep and eventually you will. If you make a very fast descent, you are much more likely to feel the effects. Always keep in mind you are narced when you feel the effects and when you don't.

 

[iztok]

For practical purposes O2 has similar narcotic properties as N2 at depth. So reducing O2 will not help there.

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

 

[RonMurray]

As others have commented - you were narced, just didn't identify the symptoms.

One of the symptoms of narcosis is euphoria and a feeling of well being. Your lack of perceived impairment, is likely a symptom of your narcosis. This is why the objective tests like math problems are helpful in identifying the level of impairment.

Another symptom of impairment is a heightened feeling of anxiety. But this is more readily identified as symptomatic of narcosis by the diver.

Breath some Nitrous Oxide at your local dentist. You won't be staggering drunk - you'll likely just feel "fine". I tried Nitrous once at my dentist - found it rather anticlimactic.

 

[Deefstes]

Thanks for all the replies. I like the idea of taking a slate and doing some math problems. Sounds like a nice objective measure.

For the record, I am not denying that I'm getting narced. As Walter said, I'm getting narced on every dive, even the shallower ones. This is why I said that I have never knowingly suffered from narcosis. I should probably have said that I have never knowingly experienced the effects of narcosis.

 

[ianr33]

Get your buddy to throw a problem at you at depth,but dont let him tell you what its going to be beforehand. Maybe he takes his reg out then grabs your fin. How do you react? Do you instantly donate your reg or do you not see the problem?

Couple of minor incidents I can think of: Cruising along at 150 in Cayman buddy gave me his reg. I instantly gave him mine in return,so there we were,side by side each on the others long hose He wanted me to test how it was breathing, but my befuddled brain failed to process that. The thought process was along the lines of problem! better donate reg!!!

Similar depth in Bonaire,unclipped spg from D ring,got it all the way in front of me before realizing I was holding the clip on the bottom end of a deco tank.

Neither of the above would have happened at 20 feet.

 

[Buoyant1]

I know I'm narced on mostly every dive...but I'm blaming the 80's on why it doesn't really affect me to the point like some people I know.