Environmental conditions effects on narcosis

[Graeme Fraser]

It is a very real thing. I’ve had the dark narc gloom and doom in cold and low viz. Not fun. I exclusively dive the Great Lakes. It seems to be relatively common for tech divers to get their Helitrox cert to use weak trimix to take the edge off the narc you can easily get here. It was recommended to me by a good number of experienced Great Lakes tech divers.

You’ve heard of happy drunks and mean drunks. Happy narc is tropical water, let’s give my octo to a fish, from everything I’ve read. Dark narc is everything from anxiety to impending doom, GTF out of here NOW!

Interesting comparison of dark and happy narc. Whilst I haven't knowingly experienced the phenomena, I've dived with buddies who have fallen into both categories. In addition I've been with one who exhibited completely, out of his brain, bombed out, oblivious narcosis, which, whilst quite funny to observe, was actually pretty scary. I'm sure without us physically ascending him he would have continued in that state until he ran out of air.

Another post mentions CO2 build-up, which I think some people experience and possibly confuse with dark narcosis. I've had a few CO2 hits myself, which does result in a deep feeling of unease. However, unlike narcosis, the effects don't necessarily clear immediately on ascent and, at least in my case, give me a stonking headache. Last time I had this was a few weeks ago doing survey work at depth on FFM. Not pleasant.

 

[Protondecay123]

I can't see how visibility, water temperature or colour of the water would affect the actual level of narcosis.
Just like Jack Hammer said, you are more aware of the situation in more challenging environment.
At least I'm checking more my awareness when I'm deep in pea soup, so I notice narcosis better when I'm specially checking for it.


Increased stress could probably affect your breathing a bit and if you start to retain CO2 that would surely affect the narcosis level. But it would be more about stress of unfamiliar diving spot/environment than the cold water, visibility or darkness

Well, solubility of gases into lipids and water is very temperature dependent. Most gases are actually more lipid soluble at higher temperatures, except for CO2. It is more soluble at colder temperatures. I've often wondered that the reported "cold water narcosis" isn't really a bigger CO2 hit/retention. If I remember correctly CO2 is 20 times more lipid soluble at standard temp than N2.