Narced???

[bkkchris]

So here is the setup. I am a pretty confident diver. 100+ dives most in Southern Cali, Rescue cert., dive with a big camera rig most of the time. A fair amount of dives in the 70-110ft range.

A few weeks ago I was diving with a buddy taking photos heading down to 100ft-ish. It was cold, I was really cold. Around 90ft I got this real bad sense of dread and doom, like I shouldn't keep going. I was kicking pretty good, but not overexertion by any means. A bit of a sense of panic came on, something I had never felt before diving, I could feel my breathing quicken and my heart rate shooting, pounding in my ears. I had to really concentrate and run all the possibilities through my head. I guessed I was narced, something I had never felt to any great degree before. I turned around and headed higher stopping around 75ft or so and started to focus on some rock or something to photograph and calm myself down. My mind was racing through all sorts of crazy stuff, what happened if I totally lost it and shot to the surface, etc., etc... After a few minutes at 75ft it passed and I continued on my dive shallower for another 45 minutes or so. But it was a humbling experience to say the least.

So... a few days ago... back in the water... hitting 60ft or so... same exact thing happens, total sense of dread and panic! I don't know if it was all just mental at that point? 60ft seems awfully shallow to be that narced??? I did the same thing... paused and went to about 45ft... same crazy thoughts running through my head... then it passed and finished an hour dive and two more hour dives all in the 50ft range with no issues.

Scary feeling whatever it was ... gonna have to watch this... Any thoughts???

 

[gcbryan]

Mainly CO2 buildup from the exertion building up in the dead spaces in your airways from shallow breathing due to the exertion....and a little narcosis thrown in.

Don't exert yourself as you get deeper and the effect will be much less. You did the right thing by getting shallower and calming yourself down. Next time if you realize what is going on and if you aren't too freaked out see if you can stay where you are and quit moving, breath deeply and calm yourself.

This will help you see how much of it is CO2 build-up and how much is narcosis.

 

[kanonfodr]

Bingo on the advice to try and isolate CO2 buildup from the actual narcosis. Also, colder/darker conditions can have an elevating effect on narcosis.

It may help to just stop for a few moments, get your bearings, do an equipment check and a buddy check. If the bad feelings still don't go away, let your buddy know that stuff aint right and get to a shallower depth. Diving is supposed to be fun, not something that freaks you out.

Peace,
Greg

 

[Diver0001]

Any thoughts???

Slow down.

R..

 

[ajduplessis]

Cold conditions is a big contributor to diving narcosis, along with very quick descents. Manage these and things will be a whole lot easier. As mentioned, reducing your depth will help alleviate the effects of narcosis.

 

[TSandM]

I'm in the CO2 camp. Exertion at depth easily causes CO2 buildup, and when you mix that with the unavoidably amount of narcosis present, it's a recipe for severe anxiety.

Since it happened to you a bit shallower as well, I'd try leaving the camera or swimming very slowly, to see if that avoids it, and if that doesn't work, take your regs in and get them checked. If the cracking pressure is set too high, it can cause this.

 

[buleetu]

whats the cracking pressure mean??

 

[jim2386]

whats the cracking pressure mean??

The pressure your lungs have to exert in order to initiate the 2nd stage in supplying air.

Regulators with very low cracking pressure will tend to free flow very easily. Regulators with high cracking pressure you have work to get the air to start flowing.

 

[marcopalla]

I don't think it is narcosis, at 40ft on the physic/physiological side, nitrox is under control (2.4 partial pressure). PPO2 is at only 0.4, so oxygen toxicity is impossible (and not narcotic).

I think the reason is on the psycological side, I think is panic/discomfort (CO2 theory is a part of this).
I've seen in the lake at 8C°, in the darkness, some strange effects, even at 30ft (experienced divers going in panic!!)
Doing photo is also a part 'cose you have to be concentrate and is a cause of stress

I've done some specific excercieses in cold water with poor visibility... to be honest I was really not at home in the cold-cold water (about 45 fahrenheit)! , for example without the mask or calculating tables groups or changing the gear with the buddy.
I remember a feeling of "breath difficulty" and "air density", a "desire to go up" but after several times...

 

[diver 85]

I would guess not narcosis.....