What is the Shallowest Depth at which You Notice Narcosis?

[Drin]

What temp did he normally dive in? We dive in the Puget Sound in the winter in temps closer to 40 with no appreciable brain freeze, and 30ft is awfully shallow for that level of narcosis regardless of the water temp.

-Adrian

 

[Mr Carcharodon]

Back in 2005 I took a class where we did a hyperbaric chamber ride to 165 fsw. I can’t say it felt any different. We did performance tests at 165 fsw, and at ambient pressure, and everyone's response time was degraded. Although the level of impairment does vary significantly. Overseas I’ve been to nearly that depth in warm clear water and again did not feel it. What you feel and your level of impairment may not be closely related.

 

[Peter69_56]

Around 73ft I think I can sometimes perceive a very slight narc. It becomes more noticeable around 86ft. At 91ft it's definitely noticeable (especially if I have any extra CO2 from current diving or exertion).

I switched from 32% Nitrox to 18/45% helium mix at 100ft once (for a few minutes) as an experiment. The difference in awareness on the two gasses left a lasting impression, which keeps me above 100 ft now. Since that experiment I made the decision that I wouldn't dive deeper without helium mix.

My wife gets hit by narc at around 40 m and she says its very noticeable change. I on the other hand have never ever noticed it ever (even to 230'), thats not to say I am not narced, just never felt the difference, however all my deep dives have been stress free and warm water so maybe that's a contributor to getting hit harder as suggested here. I like the idea of your test and want to get Trimix certified so I can do the same test on me.

 

[Drin]

My wife gets hit by narc at around 40 m and she says its very noticeable change. I on the other hand have never ever noticed it ever (even to 230')

Are you diving air that deep, Peter?

I like the idea of your test and want to get Trimix certified so I can do the same test on me.

I hope that's not the only reason you want to get Trimix certified. It's not worth the expense just for that.

-Adrian

 

[wedivebc]

I have felt the buzz at 150ft but usually by 200ft I am feeling it for sure.

 

[Locus]

Cold also have a direct impact on narcosis. My instructor years ago took me on a quick intro to twins in the middle of winter. Water temp was below 10 Celcius (50f) and he could not perform a basic valve drill at the 30ft platform. He was in 5mm wetsuit and no hoodie.

I am still not sure if it was narcosis or brain-feeeze.

I typically dive in water 43-48F, but I always wear a hood. Why did your instructor go without one? At the end of my last dive, one of my buddies lost her prescription-lens mask in the shallows and I found and retrieved it for her without my hood, which I had just taken off. I was under for only seconds in 46F water but I got the worst brain freeze of my life.

 

[LeadTurn_SD]

A modified "Martini's Law" applies to me; for me it well and truly begins at around 90 feet; but even at 60 feet I'd have to say, if I'm honest, it feels like I've already had a "Lite" beer:

90' = 1 Martini on an empty stomach
120' = 2 Martinis
150' = 3 Martinis
180' = 4 Martinis ..... better take away my car keys, and better not have anything happen during the dive that requires quick thinking on my part.

I've only been to a hair over 200' (on air), and that was 36 years ago. These days I rarely dive below 80'.

Best wishes.

 

[Storker]

I usually feel it starting to creep up on me when I pass 25m/85ft. It's not so much a "drunk" or "high" feeling, it's more sluggish thinking and mental tunnel vision. Just below 25m I'd estimate it to about one beer unit of mental sluggishness and lack of awareness.

Since I don't have enough emergency drills stored in the lizard part of my brain yet, I don't trust myself to dive safely when noticeably narced. I still haven't been deeper than 30m/100ft, partly due to the narcosis thing, partly since there's virtually no light at those depths here (less to see and photograph) and partly due to the time to NDL and rock bottom pressure being really short. Why bounce to 40m when I can do a multilevel dive dive with a max depth of 20-25m and stay submerged until my bladder starts nagging me after almost an hour?

 

[Peter69_56]

Are you diving air that deep, Peter?



I hope that's not the only reason you want to get Trimix certified. It's not worth the expense just for that.

-Adrian

Not normally although I did do one dive to that depth, normally its 40-55m.
No I want to do trimix to do some deeper dives as I love wreck diving and some of the wrecks I wish to dive are very deep so Trimix is the only way to get there safely.

 

[ajduplessis]

What temp did he normally dive in? We dive in the Puget Sound in the winter in temps closer to 40 with no appreciable brain freeze, and 30ft is awfully shallow for that level of narcosis regardless of the water temp.

About double the indicate temp (~20C)
-Adrian

I typically dive in water 43-48F, but I always wear a hood. Why did your instructor go without one? At the end of my last dive, one of my buddies lost her prescription-lens mask in the shallows and I found and retrieved it for her without my hood, which I had just taken off. I was under for only seconds in 46F water but I got the worst brain freeze of my life.

Under estimated the water temp (new site) and was intended to be we very short & shallow skills test.