Environmental conditions effects on narcosis

[Narcoz]

There seems to be a consensus that diving in a "cold, dark, limited viz" environment results in further gas narcosis than say warm tropical waters.

I'm wondering what the actual evidence is around that? Granted narcosis is hardly measurable/quantifiable but this thing about cold dark waters is being thrown out there as if it's hard fact. Could it be nocebo?

 

[Marie13]

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!

 

[Jack Hammer]

My opinion is that the narcosis is the same in dark cold water as it is in warm clear water. You are just a lot more aware of it in dark cold water.

 

[chillyinCanada]

I've had dark narcs in clear warm water. Fortunately, not that many but enough to have determined that there was a correlation with how tired I was.

 

[BRT]

My impression is a "Dark Narc" for me is from CO2. I've had this several times in warm water and once in cold. To much exercise with not enough breathing and I get the feeling of "I've got to get out of here".

 

[Heka]

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

 

[Nomad-Diver]

Regardless of how impaired I actually was, I felt less narced in bright warm water compared to cold dark water at a similar depth.
When I went deeper in warm bright water it was a happy narc, and in cold dark water definitely only ever a dark narc (perceptual narrowing etc)

 

[KenGordon]

The whole experience is different given more vis and comfort. You could be equally narced but in good vis you can see enough to be reassured. When you can only see two or three metres, it is dark in the middle of the day and you know you might accidentally end up inside a wreck it is sensible to be a bit apprehensive, chemistry adds to that.

Other aspects include the effort involved in the places which are cold and dark vs tropical diving, thus making co2 more likely an issue.

 

[undrwater]

Besides perception, are there other methods of measuring narcosis?

 

[Angelo Farina]

Narcosis is partly a physiological phenomenon, partly psychological.
Given a fixed physiological stimulus, the resulting psychological effect can be very different depending on a number of factors, both internal and environmental.
And what we experience is the psychological output, which can actually be measured with some ability tests.
I have seen at TV the US Navy performing such tests inside an hyperbaric chamber, where volunteers were narced at different depths, and then asked to solve quizzes or perform mechanical ability tests.
In my personal experience, in the sea, in clear water, I usually do not get narced if I do not exceed 50 meters depth. However, I had a couple of cases when I was tired, or water was very cold, where the effect started to be perceivable around 42-45 meters.
I did dive in lakes only a few times, and I remember having been severely narced at just 20 meters in Lago Maggiore. Water was chilling, visibility was 2 meters, the colour was dark brown, and it was the worst Nitrogen (or perhaps CO2) trip of my life.
So, based on my very limited experience of narcosis, I would answer YES, environmental conditions can play a big role.