CO2 on OC

[Grrr]

Not sure if this is the right forrum for this one, but what the hell here goes anyway.

While doing some lectures on a Mod 3 CC Inspo course recently we discussed CO2 issues (as is always the case on CC) and peoples experiences of these issues on rebreathers.

Subsequent to the course and on reflection there was a dive i did about 10 years ago, which I had experienced symptoms that I had put down to being narked at the time, however on reflection all the symptoms had an uncanny resemblance of CO2 problems, but in this instance I was on OC.

General details were a fast descent down to 51m on air, which at this depth was black as a bag. At the time I can clearly recall my breathing rate increasing and becoming very short (almost skip breathing you might say) with the feeling that my reg could n't give me enough air to breath. At the time I put this down to being narked.

However on reflection I wonder whether as well as being narked there was an element of elevated CO2 issues, which I'd not considered as being a problem on OC.

So my question is has anyone else experinced similar problems on OC.

[Finless]

Yes, when I had been working hard or was anxious. I used to push the purge button ever so slightly to give myself a very gently free-flowing reg for a few seconds until I'd got myself and my breathing back under control.

Working hard could cause a CO2 prob in my FFM if I started to pant a little bit.

Would there be enough static space on standard OC equipment to allow a CO2 build up? I suppose not breathing properly could cause it?

Oh well, I've wasted more web space without contributing anything useful.

[denismc66]

Yes this has happened to me on several occasions. Basically each case followed a rapid descent into to current resulting in what i thought was a bad case of narcosis. Each time i felt very narced with a horibble feeling of the he-be-gebees! It was only afterwards i realised it was Co2.I think a lot of o.c divers underestimate the effects of Co2

[digital_steve]

I have had CO2 issues that i put down to being narked as well.
My heart will start to thump, not quicker but just feels like a really hard beat and i felt that i could never get enough air through the reg... even though i was slowly breathing. Horrible feeling and i thought i'd swim a shallower profile to try and compensate against narcosis, it didn't really help.
This was all on 21%. I don't seem to have the same issues on richer mixes... dunno if that's placebo or not

[Finless]

Originally Posted by digital_steve

I have had CO2 issues that i put down to being narked as well.
My heart will start to thump, not quicker but just feels like a really hard beat and i felt that i could never get enough air through the reg... even though i was slowly breathing. Horrible feeling and i thought i'd swim a shallower profile to try and compensate against narcosis, it didn't really help.
This was all on 21%. I don't seem to have the same issues on richer mixes... dunno if that's placebo or not

No, it's nitrox.

[Scubee]

That would be CO2. Shallow breathing, which is fast, doesn't get rid of the CO2 in the body. A way to deal with it is to breathe deeply and slowly in, then slowly out. the way I was shown was to count - in for 5, out for 7. The longer 'out' expels more of the CO2.

Somethign to do with using all your lungs, rather than just the top portion.

At least, that was the way it was explained to me.

[David]

Originally Posted by Scubee

That would be CO2. Shallow breathing, which is fast, doesn't get rid of the CO2 in the body. A way to deal with it is to breathe deeply and slowly in, then slowly out. the way I was shown was to count - in for 5, out for 7. The longer 'out' expels more of the CO2.

Somethign to do with using all your lungs, rather than just the top portion.

At least, that was the way it was explained to me.

yup.

[Depth-junkie]

The only CO2 issue ive ever had was on OC.


Was a good few yrs ago, 57m rapid decent on Air in dotty. Cold black water @ 4c. Felt fine for the 1st 3-4 min at depth, the problems started when we started swimming round. I was struggling to keep up with my buddy. then next thing whooooooosh i felt like i was in a washing machine head spinning dizzy, could not catch my breath and my lungs felt flat like a pancake. Each breath i took from the reg felt like i was getting no air and my breathing eas very very fast short panting breaths.

I managed to grab hold of a cable a close my eyes and remember thinking cant breath, cant breath. But i could hear the reg fire on inhalation. So i managed to calm my self down and remember saying to myself of course you can breath listen theres the reg opening and closing. After about 1min my breaths became deeper and not panting breaths, but i still felt like i was inside a washing machine.

My buddy realised sum ut was not right and turned round and grabbed hold of my arm and we swam up to around 40m (at this time i could not see him, i just felt his hand on my arm guiding me up)

at 40m my breathing returned to normal and it felt like someone turned the lights back on and i could see and think straight.

I think my incident was due to skip breathing at depth trying to make sure my air lasted, Narcs and also trying to keep up with my bud who fins like a banshee.

That was the only time in my diving career that when i hit the surface i felt like, thank god i survied that one. I remember sitting on the side all kitted up and was as white as a ghost. This incident also made me sign up to a OC trimix course the next week.

If this incident happend on my breather there would have been no way i could have switched to OC as my breaths were just far to fast and shallow to even attempt it.

In CCR diving we really have to prep and dont cut corners and make CO2 a complete non event.




ATB
Gareth

[SoggyFox]

Originally Posted by Depth-junkie

If this incident happend on my breather there would have been no way i could have switched to OC as my breaths were just far to fast and shallow to even attempt it.

could you if you'd had a BOV?

[Depth-junkie]

Originally Posted by SoggyFox

could you if you'd had a BOV?

Possibly, but to be honest if it was attached to inboard it would have been gone in a jiffy. Grabbing hold of the cable for dear life was about all i could really muster for at least the 1st 40 sec's or so, and if this was on CCR i believe it would have gone from bad to worse by this stage.

Do i see CCR as dangerous ref CO2......No, if i did i would not dive one. just dont cut corners and make co2 a non event.

Ive had a m8 underweighted on a dive from 90m have to cart a big feck off lump of slate from the bottom of Dotty to enable him to stay down for all the stops. The poor basterd was working his nuts off dragging it up the slopes and holding on for all he was worth. He was diving a inspo, no CO2 work related problems at all. He finished the dive and all deco, we called him a tit for dropping 3kg of his belt for the dive. Then we went to the pub for a pint

To suffer a proper CO2 hit on an inspo you have to have fecked up big time, no spacer, no oring or over used lime. And if this happens IMHO you are in the lap of the gods. Best dont feck up as this is serious shit

Listen to your body and feelings, on the above mentioned dive i knew sum ut was not right, and i did not feel to good at least a min before i went dizzy and all to shit. I should have turned it there and there and not pushed on trying to catch up. Lessond learned for me.



ATB
Gareth