Question Ever experienced Nitrogen Narcosis?

[tarponchik]

I've been at 120+ ft for the time allowed there several times; I've been to 150+ ft several times; I've been to 185 ft once for a minute or two, never felt anything unusual. Perhaps, had I stayed there longer I might have felt something but I followed my plan: go down, take couple of shots, and get the Hell out of there.

 

[Stoo]

Narcosis is an insidious thing. As others have said, it effects different people in different ways. It affects any one person in different ways on different days.

I do a lot of what is likely considered "deeper air"... and by a lot, I mean most of my diving. My buddies and I routinely dive 100, 150, even 170+ feet on air, in part because helium isn't available in Tobermory and we never know where we're diving until we're on the water. I don't give it a second though on those 100' to 150' dives, but I am acutely aware of it beyond that. My personal "narco-guage" is my camera. There comes a point where I appreciate that there a LOT of buttons on the back of the housing and I need to really think what each one does. I did a dive on a wreck at 175' a bunch of years ago. It was dark, so my autofocus was hunting a lot. I thought I'd outsmart it by using the focus lock function and as a result, I ended up with 50 blurred images. At depth, I thought I was brilliant. That's narcosis. You don't really know it's affecting you until you "develop the film", so to speak. I'd use helium on that dive today.

I haven't read this entire thread, but I imagine there's a bunch of people saying it doesn't affect them, and to them, I say horse-pluckies. I used to volunteer at the hyperbaric chamber in Tobermory. We would take dive groups on trips in the chamber. At depth, we'd hand out silly little children's games for people to try, or ask them to do some simple arithmetic. It was both hilarious and terrifying. Everyone made a mess of whatever task they were trying to do. Now I know that I get way more narc'd in a chamber than I do in the water, for the simple reason that I know I can let myself get wasted without risk. I've joked that when I'm too old to dive, I'm getting a one-person chamber for my spare bedroom just to take narco-rides.

This may have been mentioned as well, but there is also a variation of narcosis often called dark narcosis. That's when the euphoric feeling is replaced by anxiety and perhaps fear. My opinion is that there are other factors at play with this... likely CO2 buildup. The only time I've really felt this was a deeper dive, on air, in really dark water... and a ripping current. Fighting to avoid being blown out to Newfoundland had me working REALLY hard. This was probably 30 years ago and I would NEVER attempt that dive without helium today. I legitimately thought I might die on that dive. It was stupid...

So ya, it's a thing. It's mostly manageable in rec diving depths... Beyond that, it's a different beast altogether.

 

[Stoo]

I've been at 120+ ft for the time allowed there several times; I've been to 150+ ft several times; I've been to 185 ft once for a minute or two, never felt anything unusual. Perhaps, had I stayed there longer I might have felt something but I followed my plan: go down, take couple of shots, and get the Hell out of there.

Your short time at depth meant you had limited tasks to complete, so it wasn't especially noticeable. Next time you have the opportunity to do a dive like that, take a slate, and before you dive, have someone else write a simple math problem on the slate. Simple addition, then multiply the sum by something.... and solve it at depth. While you're at it, sign your name with your regular signature. It's entertaining, but the scary thing is that at depth, you'll think you nailed it. A cold beer says you'll make a mess of it.

 

[sourdough]

Anyone know of studies related to longterm exposure to nitrogen narcosis? For example, what happens if you stay narc'd at a set depth in the chamber for an extraordinary length of time? Does the experience remain stable, wane, increase over time? What would happen if someone stayed narc'd for hours?

I'm curious because some of the more potent effects sound similar to oxygen starvation or excessive CO2.

We probably can't get this data from anything but a chamber due to the time constraints on dives, and danger involved, but in a chamber there's got to be studies on this.

I'm digging around online.

Nitrogen Narcosis In Diving - StatPearls - NCBI Bookshelf

 

[Akimbo]

Do people ever get giggly in cold, murky water, or dark narc in warm clear water?

I have never seen it, even with divers in training with full comms. Chamber runs are very different than in open sea — even a wet pot is not the same. You feel pretty safe, you are usually with friends, and there are no distractions from gear or the environment.

 

[bertschb]

I've dove the Devil's Throat in Cozumel (~130') half a dozen times over the years and never had a problem. But, on my second dive trip to a wreck in Canada 20 years ago I definitely got narc'd. Before the dive my buddy and I talked about getting a picture of the two of us at "the gun" on this particular wreck which was on the bottom at 125'. When we got there I was confused and couldn't remember what I was doing or where I was. I looked at my buddy and signaled up. We went up to the top of the wreck (60'-70'??) and finished the dive there. I remember being relieved when we were at that shallower depth. Never did get that picture of course which I regret because my dive buddy ended up passing away a few years later.

After that experience I pretty much avoid going deeper than 100' on cold water dives and I really don't have much interest in doing it on warm water dives either to be honest.

 

[100days-a-year]

Thousands of dives past 130' on air or lean nitrox. Often requiring quite a bit of exercise, amazing what being still a few breaths can do to bring you back into focus.
Dozens of friends with the same experiences.
To 240' on air a few times including once with a guy on mix who let me breathe off a reg at depth to see how noticeable the difference was.
If you're comfortable at a certain depth one day it can all change quickly when environmental conditions or exertion levels change so it is very important to dive within your comfort level and training.

 

[Celt]

Anyone know of studies related to longterm exposure to nitrogen narcosis? For example, what happens if you stay narc'd at a set depth in the chamber for an extraordinary length of time? Does the experience remain stable, wane, increase over time? What would happen if someone stayed narc'd for hours?

I'm curious because some of the more potent effects sound similar to oxygen starvation or excessive CO2.

We probably can't get this data from anything but a chamber due to the time constraints on dives, and danger involved, but in a chamber there's got to be studies on this.

I'm digging around online.

Nitrogen Narcosis In Diving - StatPearls - NCBI Bookshelf

If you go to deep you may not get back, the deeper you go the more symptoms you experience and the more debilitated you become, it would be very foolish to increase your depth if your already feeling the affects of narcosis. Never make a deep air dive if you've had a break from diving of more than a few months. Always get in some shallow dives before going anywhere near your narcosis limit and know what that limit is. A bit of planning and common sense and you have nothing to fear from narcosis.

 

[tursiops]

I taught the PADI Deep Diver course once at Buddy Dive, with three students. On Dive #3 (of the 4 required) I briefed that we'd go to 128 ft right in front of the resort, level out, do our mandatory skills, and then turn around, look out, and estimate how many garden eels we could see in the sand. THAT was actually my cognitive skills test for the folks, while they were holding depth for some multi-tasking. So we finish at depth, ascend, do our mandatory breathing off a safety bottle I'd left at 15 ft, and surfaced. During the debrief, we discussed if anyone felt narced...any tunnel vision? Any light-headedness? Any confusion? No, they all said. I asked one guy how many garden eels he'd seen; he said he started counting but when he got to 60 he got bored and they I'd tapped him and the others on the shoulder and indicated, "let's ascend." The lady said she'd estimated over 100, because she'd looked at a patch and counted ten, and then estimated there were at least ten such patches visible. The third diver was listening to the other two with a funny expression on his face. I look at him, and he said, "Garden eels? What garden eels?" He had no memory of that part of the dive, even though I'd watched him turning, looking out, scanning the sand, even pointing and counting with one of his fingers.

 

[Scraps]

Lots of divers report not “feeling” narc’ed at depths where narcosis is possible.

Similarly, lots of drunk people report not feeling drunk.

When I teach the deep dive in AOW, I do ask my students to perform various skills at depth.

What I most want out of that dive, even more important to me than the performance requirements, is for them to hardwire their brains so that, even if they feel fine on a deep dive, they assume that their cognitive skills are impaired and resolve never to alter the plan except in a more conservative direction. Know that any great ideas that occur below 30 meters are suspect. Stick with the original dive plan or make it shorter, simpler, shallower.