Rapture of the deep?

[AfterDark]

It just makes me more stupid but sometime I can't avoid it.

 

[TMHeimer]

Though Deep certified, I have only on occasion dived 100-130' and don't recall being narced, though conventional wisdom says I must've been to some degree. I would never seek to be narced on purpose. It would make the dive more dangerous and the shells harder to find.

 

[Mr Carcharodon]

How deep do you have to go to feel narced? I’ve been down to 30’m many times and never felt it. Down to 40’m a number of times and not felt it, and down to 50m a few times an not felt it. Although one time down to 50’m was in a hyperbaric chamber and the test results were marginal. That said OW diving to 50’m has not been objectively problematic. What depth can you go to? and in what conditions before it is an issue? Are there conditions like temperature, visibility or other stressor that change it?

 

[northernone]

It seems Co2 retention is a large factor for me, being "dark narced" isn't pleasant and I'd suggest I've experienced what I consider being narced as shallow as 54ft (15.6m) in uncomfortable conditions (current, dark, cold and gear trouble).

However, I've also done some careful manual photography with lights + ambient at 178ft (54m) where I didn't find my skills degenerated.

Yes, diving deep air, but I'd rather vilifying myself in a effort to provide accurate data of what I've experienced rather then vague theories. There's great threads with plenty of viewpoints and even some research presented.

Results may vary.
Cameron

 

[Subcooled]

How deep do you have to go to feel narced? I’ve been down to 30’m many times and never felt it. Down to 40’m a number of times and not felt it, and down to 50m a few times an not felt it.

At 40m gas narcosis combined with dry gloves made it difficult to operate a reel locking screw. It was noticeably frustrating and slow as compared to the same procedure at shallow depths.

Between 40m and 50m I have also detected a delay in processing the images delivered by the eyes. This lead to some rather interesting overlaid images for a second or two. And no, I don't think that oxygen toxicity was the cause on that leisurely and short dive to ppO2=1,15. Darkness and low visibility of course made the phenomenon detectable.

The combination of difficulty of seeing and gas narcosis also made me dive into a "tunnel" at -40m that proved to be not a tunnel but the black and muddy bottom. Hitting the bottom felt confusing to say the least

So, when the senses operate at their limits and one adds some slowness due to gas narcosis, things start to happen (to me at least). I'm sure that stress or fear would similarly work as catalysts.

I would not dive below -40m in a low visibility overhead environment on air, as the risks start to become quite real and relevant as I have noticed. I'm sure that there are environmental conditions where -50m can be done by some on air with acceptable risk.

As far as I understand, the intensity of gas narcosis follows a sigmoid curve and the effects start to grow faster perhaps somewhere around 60m. See Nitrogen narcosis - Wikipedia, the free encyclopedia for signs and symptoms. It is a very good article. The list is very true and I have experienced everything except fear and laughter of the signs and symptoms listed at 1-6 ATA.

 

[Sunn]

50m on air does indeed make one mentally incapacitated which does not come without real risk. Slightly more shallow depths can be relaxing, though. It is like recreational use of akcohol: it can be good and it can kill you.

sure...

when you dive deep (on air), you have to know the risks you take

I like it, but will never go deep with someone not well known for years... and everybody has his own feeling about what is "deep". Remember that divers looking for corals were regularly diving at more than 300 ft in the Mediterranean... ok, some of them limp or hobble...

 

[Sunn]

Have you heard about PSAI Narcosis Management® training ?
"PSAI is the only agency offering Deep Air training awareness down to 73 meters ~ (240 feet) taught in six levels." that's what I found on their website.
One of these days, I'd like to follow this level VI, unfortunately no instructor around... and I won't go to US only for this.

 

[Storker]

Somewhere near 30m, I notice I'm getting slower, and my ability to focus on more than one single thing at a time is impaired. I don't enjoy being stupid, particularly when I'm in an environment where the wrong decision can have serious consequences.

Since I'm not trimix certified, I normally don't like to go particularly deeper. And since I'm not deco certified either, I don't see much point in what would effectively be a bounce dive.

 

[UnixMarine]

I normally do not get appreciatively narced down to 130. That being said, the last time I dove air in Lake Travis down to 130, I did. I started noticing it at 122 and at 130, I was getting tunneled and had to go back up. Water was relatively warm and this was abnormal for me. Some days are different than others. Narcosis is like that.

 

[sheeper]

at the 140 foot range i start to know i'm narced. and i feel great. yes, i'm deep, tec, deco, trimix, etc so i don't go past 150 without a little He. But i'll enjoy that 140 feeling from time to time. Deeper than 150, i feel very narced and at 160 i start to worry about my ability to function.