Alarming and Dangerous Incident please read

[RonFrank]

My best guess is probably that your reg is cheap/rental and the decreased efficiency of gas delivery, combined with high demand due to you being a new diver made it hard to breathe.

Get a better reg, make sure that your valve is all the way open, and take it slow and easy... When you notice that you are breathing heavy try to take controlled deep breaths. You don't want to breathe rapidly, but you do want to take full inhales and then exhale completely to expell the CO2 in your lungs.

He was diving a SP S600, and likely an MK25 first stage? With 118 dives under the belt, I would *think* he'd have breathing worked out for a 75' dive...

 

[Doubles]

Just wanted to thank Peter84 for posting this issue and also to say again, glad it all turned out well.

It has been an interesting thread and has revealed the varying and differing experiences of narcossis.

Very thought provoking

 

[jepuskar]

Peter,

What kind of BC did you have on? I find that unless I dive a stainless steel backplate and a 36lb Wing I will most certainly be narced at 10 feet or below.

J

 

[theskull]

. . . I went back dowm to find the two individuals diving with me to let them know I was OK and to do a proper gassing off ascent. . .
Peter

Why has noone questioned this action?!

He THOUGHT there was something wrong with his gas or his reg, but he made a solo descent immediately after a panicked emergency ascent!!

If something (other than narcosis) was truly wrong, boy were you set up for a tragedy by making a solo dive at this point!

theskull

 

[LAJim]

I agree with theskull. This story is fishy. Dark narks are no fun. But if anything forces you to make an emergency ascent: panic, dark narc, authentic gas or equipment problems - then the dive is over - certainly until the buddy group reunites on the surface. If someone on my team surfaced thinking they had bad air then we would all have a nice surface swim home and not breath any more tank gas until it was all sorted out.

 

[BabyDuck]

i vote co2 hit too...interesting thread.

i can't get over deciding to leave 2 perfectly good gas sources. just goes to show you how fluky thought processes get under the influence of weird happenin's underwater...

 

[GDI]

I respectfully disagree with this. Maybe the OP wasn't narced but it was indeed possible; I had a dark narc diving air at 70 feet on the Regina in Lake Huron. I recognized what was going on, refused to drop my reg and bolt to the surface like my head was telling me; instead I signalled my buddy and we ascended a few feet at a time. I was at 50 feet before the feeling went away. I've been narced on an air dive that had a max depth of 40-50 feet, I was watching students on their final dive and couldn't figure out why they had stopped in the shallows--it was because they were doing their safety stop, I had no clue. I dove to 135' on 27% once and was narced out of my mind, my buddy had to drag me by the hand to a shallower depth. You don't have to be deep to be narced though, there are a lot of other factors that can contribute to a narcosis hit. I never noticed being narced until after I had almost 300 dives although I'm sure I was to some extent. The more I dive the more I notice the impairment from the nitrogen.
Ber :lilbunny:

Your points noted and yes possible but not likely IMO. In your dive cold water temps could also have been a contributing factor, in building up your CO2 and thus a "dark narc" as some are calling it. There could have been other things as well But it is still a lessor chance that it may have been caused by just diving to 75 ft, there would need to have been other considerations to call this incident a narcosis hit.

Add to this perhaps fatigue and a deceptive workload while under water. Your own very excitement going into the dive may have caused you not to open the valve correctly, it doesn't take much. Thus the deeper you went and the longer you stayed the more air your body will demand. Your breathing unconsciously increases as does the demand for more air and before you know it you are having difficulty breathing.

In my statement here from an earlier post I am suggesting a CO2 build up in addition to the valve as a cause for his lacking of a breathable volume of air at depth.

Now if he had a CO2 induced breathing concern then it may have worsened regardless of his ascent or not subject to his possibly getting control of the situation. Granted that Narcosis is a personal thing that will effect each divier differently. I do not find it all that likely that a diver with 118 dives would be impaired by it as a result of depth alone.

 

[GDI]

Peter,

What kind of BC did you have on? I find that unless I dive a stainless steel backplate and a 36lb Wing I will most certainly be narced at 10 feet or below.

J

OK....?

 

[lamont]

He was diving a SP S600, and likely an MK25 first stage? With 118 dives under the belt, I would *think* he'd have breathing worked out for a 75' dive...

Hmmm... yeah, I skimmed and missed the post where he mentioned 118 dives...

And the S600/Mk25 reg makes it less likely it was a crappy reg situation, but even well designed regs can performly poorly when they're in need of a tuneup -- but with 118 dives I'll trust him that he thought it was delivering okay...

I'm now voting simple dark narc and CO2 buildup cycle... When I had that many dives I was still working on breathing correctly and not building up CO2 and had a lot of experience in 45-55F water at 100 fsw (and sketchy narcs at least every few dives to begin with...)

 

[TheRedHead]

I think it would be instructive in AOW class as part of the deep dive to have the diver fin at maximum effort at 100 feet for a couple of minutes in order to understand how extreme exertion can exacerbate narcosis.