CO2 retention, Overexertion, and Panic

[Lopez116]

I had what I would call a full blown panic attack on a dive today. I was always puzzled by a diver’s urge to spit out the reg and bolt to the surface and never thought it was possible that I would feel that way; until today.

Was on a shore dive in pretty intense current today. We swam into the current for maybe 20 yards, hid in a cavern-like spot to catch our breath, continued on another 25-35 yards into the current, took refuge again behind a coral head, went on another 10 yards or so, and then “flew” with the current almost back to the start and did it over again with a 5 min break of resting in between.

When I approached the point where we turned around the second time, I felt an incredible sensation that I could not breathe enough. It sounds weird but it felt like my throat was super dry, like I needed to swallow, and like I couldn’t get that deep breath of air - like I was just breathing in/out but it wasn’t having a measurable effect on alleviating my shortness of breath. I felt myself getting more and more anxious and could feel my body getting warm and tingly and my heart rate getting faster and faster. I felt like I needed to take a sip or water or breathe ambient air without my reg in. The urge to spit out my reg and get to the surface felt very strong so I signaled my buddy that I wanted to turn around now and abort the dive immediately.

I kept my hand on my second stage to physically remind myself not to spit it out no matter what and I ascended slowly, did my safety stop (where I finally calmed down), and ended the dive.

Max depth was 55’, avg probably 50’, temp 84, viz 40-50’, current very strong

I have near 300 dives to date and while I’ve experienced anxiety on dives before, nothing like this. I’m a little shooken up to be totally honest, and a little nervous about diving my next dive (whenever that is).

During the dive, I was working hard for most of it. Short of breath a lot, but not extremely. I always thought you “can’t overbreathe a regulator” (I have a Legend LX), so I wasn’t really concerned about that. I knew logically I was getting enough air. I also make concerned efforts to breathe out for a good length of time (maybe even longer than inspiration) to avoid CO2 retention.

I am 35, 6’0”, 206 lbs. I am overweight, but not obese. Admittedly, I do little exercise when not diving, other than go on daily walks of about 1.5 miles.

Is this a case of CO2 retention?

Overexertion?

Detuned reg?

Poor physical fitness?

Thanks for any insight or advice.

 

[KenGordon]

Well done for talking about this. I would guess co2 buildup but why i cannot say. It could be anything you suggest and maybe some others we’ve not thought of.

At the end of the day though, it is all about physiology and the metabolic process. Don’t get upset about it, just be aware that limits exist and it can be unpleasant to reach them.

 

[Bubblesong]

I think you have it right, because even on land, when yawning I feel like I can’t get enough air breathed in, unless I try to really empty my lungs. But still can’t overdue that, or I end up light headed from too much oxygen, which is still less unpleasant than feeling like i can’t breath.

 

[scubadada]

I have only ended up short of breath on a few dives. In general, it has seemed secondary to extraordinary exertion. Unlike you, I exercise every day and am familiar with my exertion limits. On a couple of occasions, I have felt that my exertion was limited by my ability to exhale, whether this was due to CO2 or not is a matter of debate. In either case, I take a breather, to sufficiently recover and move on.

 

[northernone]

Our minds and bodies do odd things underwater sometimes. I'd agree with your suggestions of working too hard and co2 retention accelerating the vicious loop. Sounds like you handled it well once realized, glad you kept your head.

Do you have some calmer dive sites to build back up your comfort underwater? For me, after a good scare I do a few dozen dives in nicer conditions before returning to the conditions related to the situation. Just for mental calm and reassuring myself.

I'm not a big fan of "facing my fears" underwater, it's where I am at peace and I need to be comfortable.

 

[Lopez116]

Thanks all for the responses so far. I’m slightly intrigued by the science and mechanism of CO2 retention and panic now. Nitrogen narcosis is often talked about in cert classes but not CO2.

Yes, I have access to lots of those easy sites thankfully. I know I need to get “back on the horse” sooner rather than later, but ease back in.

 

[aquacat8]

Was your reg in “pre dive” mode perhaps?

 

[aquacat8]

I have read that for a bigger diver leaving the reg in pre-dive mode may create a sensation of restricted gas delivery.

 

[TMHeimer]

Our minds and bodies do odd things underwater sometimes. I'd agree with your suggestions of working too hard and co2 retention accelerating the vicious loop. Sounds like you handled it well once realized, glad you kept your head.

Do you have some calmer dive sites to build back up your comfort underwater? For me, after a good scare I do a few dozen dives in nicer conditions before returning to the conditions related to the situation. Just for mental calm and reassuring myself.

I'm not a big fan of "facing my fears" underwater, it's where I am at peace and I need to be comfortable.

Yes, build back up with easier, perhaps shallow sites. Thanks for sharing this, as it points out that even experienced divers can have this problem. You did well to adhere to training--stop, think, and act (hold the reg in). My thought has always been that even the most experienced divers can face stress that could lead to panic. I've been unfomfortable several times--mostly due to current or cramping-- but nothing serious, so I don't know how I would've reacted (knock wood).
I don't think you mentioned where you were diving in 84 degree water.

 

[BRT]

I have experience this a few times, a little deeper, around 70'. Finally figured out that if I did a complete exhale to the bottom of my lungs, a deep breath and another complete exhale the symptoms and the feeling of panic disappeared. I believe it is CO2 narcosis.