Bad dive at Ginnie

[a64pilot]

OK, from what little I know about about CO2 poisoning or a hit if you will it sounds like the symptoms, but how do you get a CO2 hit open circuit unless your breathing is really, really screwed up or of course there is a high level of CO2 in the gas supply?

[Jim Wyatt]

Holy crap that sounds like a bad time. I can't imagine why you decided to solo dive, sounds like you were a ball of stress and now realize how quickly that can escalate.

I think you forgot the most important part, cave diving is only for fun, once the fun stops, leave.

There are no "go for it" moments in cave diving. Leave that for jumping out of planes, killing our countries enemies, hitting on hot chicks or football. If you find yourself pushing for whatever reason, stop.

Thanks for the honesty though, shows you are open enough to learn from your mistakes.

Nicely said, Thank you neighbor.

[MORGAN]

OK, from what little I know about about CO2 poisoning or a hit if you will it sounds like the symptoms, but how do you get a CO2 hit open circuit unless your breathing is really, really screwed up or of course there is a high level of CO2 in the gas supply?

Sometimes when people breathe rapidly they also breathe more shallowly. This reduces alveolar ventilation and can cause CO2 retention.

In the average adult about 150 mL of each breath is "dead space". About 2 mL per kg of ideal body weight. It is the air that occupies the large airways and doesn't participate in gas exchange. So only the volume of the breath > 150 mL actually exchanges O2 and CO2. If you were to breath at a tidal volume of less than 150 mL, it wouldn't matter how fast you were breathing; from a gas exchange standpoint it would be as if you weren't breathing at all.

So your idea of the breathing being really screwed up is probably right.

Mike

[nkavallar]

To reply a few of you:

- I was diving BM 108's with 32% Nitrox, my deco bottle contained 100% O2
- I was not at the bottom of the gallery pull and gliding, I was near the top left
- The loose cover made it a little harder to breath and when you breath hard (effort) and exert yourself you build up CO2
- I have made about 30 cave dives there (from intro to apprentice of which about 10 were solo) and have about 60 total cave dives (At Ginnie, Manatee, Peacock (P1 & OG), JB)
- I did not test my tanks for CO2 only O2, but I dont think the tanks contained CO2


I believe it was a combination of external mental stress and anxiety as well as CO2 build up, I should have turned earlier in the Gallery but pushed it thinking it would get better.
When I found myself just following arrows into the cave I knew something was wrong but for some unexplainable reason kept going (I wanted to turn but didn't, no idea why)
until I reached the point where I just couldn't do it anymore.
This should have been an easy dive, and I've done longer and more complex dives before (I dove Hill 400 to 1100 feet with my instructor which went beautifully, Also dove
peacock to 1100 feet on 1/6th)

[Dsix36]

I am glad that you survived your little ordeal and had the balls to post about it for others (and yourself) to learn from it.

[cerich]

another possibility, not really common but...


http://www.ncbi.nlm.nih.gov/pubmed/8574121

Sometimes when people breathe rapidly they also breathe more shallowly. This reduces alveolar ventilation and can cause CO2 retention.

In the average adult about 150 mL of each breath is "dead space". About 2 mL per kg of ideal body weight. It is the air that occupies the large airways and doesn't participate in gas exchange. So only the volume of the breath > 150 mL actually exchanges O2 and CO2. If you were to breath at a tidal volume of less than 150 mL, it wouldn't matter how fast you were breathing; from a gas exchange standpoint it would be as if you weren't breathing at all.

So your idea of the breathing being really screwed up is probably right.

Mike

[cerich]

- The loose cover made it a little harder to breath and when you breath hard (effort) and exert yourself you build up CO2

no it didn't. The diaphragm was held in place by the water, otherwise you would have been breathing really wet. The WOB would have remained the same.

[KMD]

- I have made about 30 cave dives there (from intro to apprentice of which about 10 were solo) and have about 60 total cave dives (At Ginnie, Manatee, Peacock (P1 & OG), JB)

At 60 total cave dives, none of which were at the full cave, what made you think that you had the training, skills, and experience to conduct solo cave dives?

[nkavallar]

At 60 total cave dives, none of which were at the full cave, what made you think that you had the training, skills, and experience to conduct solo cave dives?

While I don't mind answering the question, I don't want this to be a solo diving thread. As I said before, I felt comfortable at the time with my skill and experience to do minor solo diving.

[Sludge]

I'm a big proponent of solo diving, if done safely. By "safely" I mean taking extra precautions over what you would do with buddy diving. First, I think a diver in training should limit himself to several levels below his level of training; I think someone with an Apprentice card should only do cavern dives solo. Full cave divers should limit themselves to intro-level dives until they have lots of full-cave dives, then apprentice-level for awhile... I didn't start doing real full-cave dives solo until I had about 400 cave dives.

I also never noticed anything in your posts about buddy bottles. I wouldn't even dive a cavern solo without one. For full-cave solo dives, I breathe a stage only, half in, half out, and never touch my backgas. If I want a longer dive, I breathe two stages one-third each.

Solo's great, as long as you take the extra precautions to make it safe.