CO2 retention question

[HarryH97]

Hey Harry, having originally trained in the great lakes, I am aquainted with lo vis and variable conditions. Granted I would love a dive sherpa and will audition any who volunteer, the fact remains that what doesn't kill me makes me stronger. So if beach diving in doubles and stages is all I can get, I'll do it. As long as maciek doesn't fry us topside. I'll just keep the O2 tanks away from him. But I am seriously considering a trip up there but need to wait for new seals on the old drysuit. I'l let you know. Maciek are you with me? Jon? Gina?

YES! Keep the O2 away from the FIRE MASTER!! :11:
H2

 

[coralcuts]

YES! Keep the O2 away from the FIRE MASTER!! :11:
H2

I still have burned in memory the maniacal laugh as he reached for more starter fluid!

 

[mweitz]

Uh, DIR teaches all of that, but as theory as I recall. Can anyone post any references to any of the things posted above? Nobody knows what causes narcosis, nobody is sure how O2 is equated into the mixture, and IF the theory is correct, then CO2 is highly narcotic.

BTW, I believe that 30/30 is the recommended mix for the 80 - 120 range ...

Mark

 

[HarryH97]

Uh, DIR teaches all of that, but as theory as I recall. Can anyone post any references to any of the things posted above? Nobody knows what causes narcosis, nobody is sure how O2 is equated into the mixture, and IF the theory is correct, then CO2 is highly narcotic.

BTW, I believe that 30/30 is the recommended mix for the 80 - 120 range ...

Mark

Mark,
How are things down in NorCal? You too need to come up here to get some...Had two great dives today in the rec range that easily could've been a T1 dive.

You'll probably need to do some searching on lipid soluability of gases which is the generally accepted correlator for narcotic potency. All the gases being breathed in increasing partial pressures are either coming in or going out of the body. If it's not the gases, what else could it be causing narcosis? The hard part is finding an accurate measure of the various gases in the body and it's true narcotic potency. O2 and CO2 is even harder because it's metabolized and makes accuracy even more difficult than that of inert gases (He, N2). And we know that is already hard enough with each body's composition of fat, muscle, and tissues being different not to mention the overall aerobic fitness of the body. Whether it's 5x, 50x, 120x, or 130x more than N2, it's bad, very bad. Godd news is that it's not coming into the body in the volumes that the other gases are coming in O2, N2, He, since it's a by-product. So, small highly narcotic doses coming in and than metabolized and exhaled. That is, unless you're producing more than what's getting cleared thru the body.

Have fun at PT Lobos!
OK, time to go to bed.

Sincerely,
H2

 

[redrover]

Hi,
I apologize for intruding but some of the DIR people said it was ok to ask questions here a while back so here I go with what I’m sure is a stupid question. Just when I think I’m ‘getting’ a few things, something like this comes along and I feel back to ground zero. Would you please help me understand this?

From the original post I interpreted he dove on AIR to 85’ for 15 min. and was told diving on AIR was inappropriate on any dive. (Is this incorrect?) Diving AIR was the cause of his headache. I do get that it appears you folks here think the suit unzipper was incorrect – well I think that is what you said. (Forgive me for not understanding the other gas stuff yet, I’m working on it.) But….

Ok, I’m a Rec pretty fish looker only trained to dive on AIR and recommended to stay above 100 feet. I’m old and have to work pretty hard sometimes to keep up with my gonzo type buddies and do dive to 85’ on occasion. I’d have to look at my logs to be sure but I think I’ve been there for at least 15 min, although probably under a dozen times. I don’t get headaches, not trashed after (actually they complain of fatigue) and I thought it was ok to do.
I think somehow I’m missing some major part in the answers to his question. It struck me, the suit unzipper was incorrect from the git go at breathing AIR, and that this gas was inappropriate to breathe on ANY dive. Since no one, including wetvet thought the comment was absurd my conclusion is; I am an idiot. Have I neglected to notice a basic DIR principal – never dive AIR, only combined gases? I never considered that since so many people do just dive on AIR. I keep finding ways people dive vastly different than why or how I am (it’s fascinating) so I am an embarrassed idiot too. Please help me see where I goofed.
Thank you.

 

[mweitz]

Yeah H2, I'm familiar with the Meyer-Overton rule, but some gasses don't fit the model, and we don't know why. I personally believe the correlation between gasses and narcosis is going to be much more complex when we figure it out…

With that said, I haven’t really dived He so can’t comment as to how effective it is at combating Narcosis. You also have to take into consideration the placebo effect when diving other mixtures. It would be interesting to see a double blind study utilizing Triox, Nitrox and Air to 80’ or so.

I personally believe that the GUE standard gasses are the safest way to dive, and follow the guidelines. I just think that there may be a bit more to the story …

Mark

 

[RTodd]

Hi,
I apologize for intruding but some of the DIR people said it was ok to ask questions here a while back so here I go with what I’m sure is a stupid question. Just when I think I’m ‘getting’ a few things, something like this comes along and I feel back to ground zero. Would you please help me understand this?

From the original post I interpreted he dove on AIR to 85’ for 15 min. and was told diving on AIR was inappropriate on any dive. (Is this incorrect?) Diving AIR was the cause of his headache. I do get that it appears you folks here think the suit unzipper was incorrect – well I think that is what you said. (Forgive me for not understanding the other gas stuff yet, I’m working on it.) But….

Ok, I’m a Rec pretty fish looker only trained to dive on AIR and recommended to stay above 100 feet. I’m old and have to work pretty hard sometimes to keep up with my gonzo type buddies and do dive to 85’ on occasion. I’d have to look at my logs to be sure but I think I’ve been there for at least 15 min, although probably under a dozen times. I don’t get headaches, not trashed after (actually they complain of fatigue) and I thought it was ok to do.
I think somehow I’m missing some major part in the answers to his question. It struck me, the suit unzipper was incorrect from the git go at breathing AIR, and that this gas was inappropriate to breathe on ANY dive. Since no one, including wetvet thought the comment was absurd my conclusion is; I am an idiot. Have I neglected to notice a basic DIR principal – never dive AIR, only combined gases? I never considered that since so many people do just dive on AIR. I keep finding ways people dive vastly different than why or how I am (it’s fascinating) so I am an embarrassed idiot too. Please help me see where I goofed.
Thank you.

Leaving out short 30' dives (where even there 32% is beneficial but not "quite" as necessary), there is no diving range where air is approproate. Down to 80' 32% is your best choice, between 80-100 trimix is optimal but availability and the dive dictate whether you switch to mix. Below 100', due to narcosis, trimix is really the only gas to use. Does that answer your question? As for for the original question, the bulk of the problem was most likely the neck seal on the drysuit being too tight.

 

[HarryH97]

Yeah H2, I'm familiar with the Meyer-Overton rule, but some gasses don't fit the model, and we don't know why. I personally believe the correlation between gasses and narcosis is going to be much more complex when we figure it out…

With that said, I haven’t really dived He so can’t comment as to how effective it is at combating Narcosis. You also have to take into consideration the placebo effect when diving other mixtures. It would be interesting to see a double blind study utilizing Triox, Nitrox and Air to 80’ or so.

I personally believe that the GUE standard gasses are the safest way to dive, and follow the guidelines. I just think that there may be a bit more to the story …

Mark

Mark,
You're absolutely right, the variation between each human body is just too great to just use one formula. I don't believe there's a way to even empirically capture all the variables to even arrive at a "reliable" personal narcotic level formula since how each human body feels and its condition changes from day to day, week to week, month to month. I think it's far too complex to model and although this may have academic value, it'll have very limited real applicability with the wide variability of the human body. The effects of compressed gases on each diver only comes from experience and knowing what's best for your body and how it reacts to different mixes. I've personally done tests with all three mixes. There's nothing placebo with use of 30/30 in 80' - it is that good, especially if you are going beyond NDL/MDL. Deco from air or EAN32 just doesn't work nearly as well as mixes with at least 30% He. You can easily do your own tests with air and EAN32. Make sure it's a working dive both from a mental problem solving/multiple scenarios and with physical exertion. Make sure ascent profiles are identical across the board and record how you feel immediately on the surface, and in 1 hour intervals afterwards for 6-8 hours (from tireness to yawning to soreness to mental sharpness). To make sure you're starting on the same baseline, ensure that you've also got plenty of rest, well hydrated and not feeling outside induced stress during this test process.

During the post dive, you should feel a noticeable decrease in "post-dive stress" with using the right gases (EAN32 over air and later use of 30/30). Diving the right gases gives you an incredible advantage. I know I either dove the wrong gas or didn't shape my curve correctly if my mind can't rapdily do the scuba math/critical thinking a few hours later or if I don't feel like running a 100m sprint. With the right gases and deco, I always feel like superman and can feel my mind spit out calculations 4-6-8 hours like a sharpened razor after the dive and also do a 100m sprint on the spot, anytime. No tiredness whatsoever. If the test a try sometime. The pipeline out at breakwater we dove would be good testing grounds.

Regardness of what gas, we know we are going to get narc'd, it's all a matter of how much/degree we want to get narc'd. Sometimes we deliberately choose to "feel good" and get a good night's rest after the dive. In that circumstance, the elixir of choice would be air at recreational depths with a "working" dive. I always sleep like a baby several hours after a dive like that. But that's a deliberate decision, and I'm not the designated driver!

Sincerely,
H2

 

[HarryH97]

Have I neglected to notice a basic DIR principal – never dive AIR, only combined gases? I never considered that since so many people do just dive on AIR. I keep finding ways people dive vastly different than why or how I am (it’s fascinating) so I am an embarrassed idiot too. Please help me see where I goofed.
Thank you.

For DIR divers with easy access to air, nitrox and trimix, diving the right gases is easy. For others, AIR may be the only option. However, with training, you recognize the real risks and benefits associated with all the considerations. Hopefully making reasoned deliberate choices and determining your limitations based on the choices you make in areas of gas, buddy, equipment, environment, etc... will lead to signficantly safer and more importantly a far more FUN diving experience by mitigating risks before and while they occur.

Sincerely,
H2

 

[redrover]

Leaving out short 30' dives (where even there 32% is beneficial but not "quite" as necessary), there is no diving range where air is approproate. Down to 80' 32% is your best choice, between 80-100 trimix is optimal but availability and the dive dictate whether you switch to mix. Below 100', due to narcosis, trimix is really the only gas to use. Does that answer your question? As for for the original question, the bulk of the problem was most likely the neck seal on the drysuit being too tight.

Ah, yes I did miss this, sigh. So much to learn.

Thank you. PM sent for additional clarification.