Narcosis -- insidious and subtle

[Airleron]

Thanks Lynne for telling your story. I don't normally do deep dives, I stay above 80 ft most of the time. But the handful I have done, I expected to feel narced and didn't. When we did our check out for AOW Deep Dive, we had to write our name and address, backwards, on our slate. I accomplished it without difficulty. I just figured I was a person who "doesn't get narced".

Ha....naive thinking. I will never, ever assume this again.

 

[DevonDiver]

I think that the 'puzzles' often used to test for narcosis on AOW deep dives often fall short of the mark. They neither demonstrate novel problem solving (including skills developed in dry land in our normal lives) nor the impact of CO2 build-up.

When I do AOW 'narc tests' I normally include an 'accelerated swim' to get the divers panting a little bit first.... that can have more dramatic effects on the test results. I also try and make the test more applicable to real diver problem solving.

You wouldn't believe the trouble that my huffing and puffing divers have with 'simple task' of swapping their fins from foot-to-foot at 30m.... Especially when the bottom is silty..and they are meant to be hovering...

 

[MXGratefulDiver]

I think that the 'puzzles' often used to test for narcosis on AOW deep dives often fall short of the mark. They neither demonstrate novel problem solving (including skills developed in dry land in our normal lives) nor the impact of CO2 build-up.

When I do AOW 'narc tests' I normally include an 'accelerated swim' to get the divers panting a little bit first.... that can have more dramatic effects on the test results. I also try and make the test more applicable to real diver problem solving.

You wouldn't believe the trouble that my huffing and puffing divers have with 'simple task' of swapping their fins from foot-to-foot at 30m.... Especially when the bottom is silty..and they are meant to be hovering...

My deep dive test is to swim up to my students and slash my hand across my throat. It's interesting to see how long it takes them to process what that means. I had one student look at me quizzically and then check her dive computer. It wasn't until I flashed my light at her, repeated the signal, and she noticed that I didn't have a regulator in my mouth that it occurred to her I might be asking for air ... :shocked2:

She told me later that she had felt completely "normal" at the time ...

... Bob (Grateful Diver)

 

[Mike Boswell]

Today i was diving solo in 185 (on air) in a strong current. I shot a large fish, grabbed it, knifed it in the head and held position on the bottom, while swimming and kept looking for the 400 lb bull shark I had seen 60 seconds earlier. I tried to quickly unhook a lift bag, and put a stringer through the fish and inflate a lift bag ASAP.

I was kinda stressed out about the shark. got the bag inflated and sent the fish up. Then quickly loaded the shaft back into the speargun and tried to wrap the line around the muzzle and the mechanical line release (mostly by touch while looking for the shark). I tried a couple times and couldn't get the line right and then it kept falling off the line release. this is normally a very quick and easy task, that I can do without hardly looking.


I couldn't figure out why the line release would not hold the line. I assumed i was missing it in my wrapping action and had to really concentrate. Once again the line release just toggled without holding the line. I stopped for a good 10 seconds, and went through the mental exercise or internal dialog "you know you are narced, now think HARD about why this would occur" ... is the gun really broken??????

I then realized that the shaft was inserted upside down, so the line release would not engage (it was still in the "fire" position). This is an incredibly stupid novice mistake to put the shaft in upside down and then not realize immediately that the line release wouldn't work. If I was doing this in the garage, I would have immediately checked if the shaft was in the gun right, but narcosis makes you stupid.

My ability to solve even common, easy, problems was significantly compromised, even though I didn't feel particularly narced and I do this dive pretty frequently.

Yeah, Yeah, Yeah ... But for God's sake, how big was the damn FISH!?! Any Pictures?

 

[dumpsterDiver]

Yeah, Yeah, Yeah ... But for God's sake, how big was the damn FISH!?! Any Pictures?

Yeah, I was very disappointed. Probably 50-60 lb cobia (which is my favorite fish to eat) was apparently eaten by shark(s). By the time we recovered the drifting lift bag, 1.6 miles from the dive site, the 400 lb test fishing line was cut cleanly off. Possibly my biggest cobia..lost to the sharks. It was 6 ft seas and my buddy never saw the bag surface.

It was an interesting day with wind and squalls and rough seas. My buddy on the boat never saw my 6 ft SMB ascend either and I was picked up about 1.2 miles away after my drifting deco, but only after I made good use of my pressure proof canister and small hand held VHF radio First time I actually had to use it.

 

[gcbryan]

My deep dive test is to swim up to my students and slash my hand across my throat. It's interesting to see how long it takes them to process what that means. I had one student look at me quizzically and then check her dive computer. It wasn't until I flashed my light at her, repeated the signal, and she noticed that I didn't have a regulator in my mouth that it occurred to her I might be asking for air ... :shocked2:

She told me later that she had felt completely "normal" at the time ...

... Bob (Grateful Diver)

That's funny story and an interesting test and I'm sure it's a good one. The funny thing is I took a drysuit cert course when I first got back into diving as a refresher and to learn to use a drysuit and we were in the pool and my instructor did what you did. The person she did it to just stared at her so it's not always a matter of being narced

 

[Airleron]

Wow Bob, that test will wake you up in the mornin'. I would guess at that time, I probably would have had the same response. Which obviously is bad.:blinking:

 

[MXGratefulDiver]

That's funny story and an interesting test and I'm sure it's a good one. The funny thing is I took a drysuit cert course when I first got back into diving as a refresher and to learn to use a drysuit and we were in the pool and my instructor did what you did. The person she did it to just stared at her so it's not always a matter of being narced

Wow Bob, that test will wake you up in the mornin'. I would guess at that time, I probably would have had the same response. Which obviously is bad.:blinking:

... which is why I've learned to test my students for OOA response in the shallows before we do our deep dive ...

... Bob (Grateful Diver)

 

[Mike Boswell]

I think that the 'puzzles' often used to test for narcosis on AOW deep dives often fall short of the mark. They neither demonstrate novel problem solving (including skills developed in dry land in our normal lives) nor the impact of CO2 build-up.

When I do AOW 'narc tests' I normally include an 'accelerated swim' to get the divers panting a little bit first.... that can have more dramatic effects on the test results. I also try and make the test more applicable to real diver problem solving.

You wouldn't believe the trouble that my huffing and puffing divers have with 'simple task' of swapping their fins from foot-to-foot at 30m.... Especially when the bottom is silty..and they are meant to be hovering...

My wife and I did the deep dive together. We faced the instructor at 130 feet, and did some exercises. We performed brilliantly, and we both passed with flying colors.

Thing is, neither of us can remember any of it.

 

[The Chairman]

I've yet to experience the sort of drunk-narcosis people generally talk about.

There's a reason why you haven't experienced it. That type of narcosis is an urban legend. I remember my instructor telling me that I would try to give my regulator to a fish. It never happens that way.

A drunk has two main ways they know that they are impaired.

• Balance: they can't walk straight. Unfortunately we don't walk underwater.
• Slurred speech: It's obvious to even the drunk. Unfortunately, we don't talk underwater.

Inevitably, the question arises as to HOW to tell when you are narced. It's easy: Check your depth gauge. Every additional atmosphere is like drinking a martini. Like liquor, there seems to be a non-linear effect of depth. The deeper you get the more the depth impairs you. But it's not the "drunk" narcosis of urban legend. It's simply a decrease in your ability to reason. Original thought becomes harder and harder. So, if you have done your training correctly, most of the problems you encounter will be well rehearsed and doable., However, if your problem is unusual, your ability to resolve it will be far more onerous.

So the next time you're at 100 feet. Remember you've had three martinis already and try to avoid taking any risks.