Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
My first thought when I read the post was an analogy......
would you practice driving drunk to see how it affects you? A bit tongue in cheek but still.....
certainly dives that are layered in good choices for safety could be used as tests for narcosis affects...but there are so many variables that any results would be highly anecdotal.
Best to use air/Nitrox for 100’ dives or less and throw some He in there when deeper. Several progressive agencies use an EAD of 100’ for a reason.
I'd like to skip rehashing the getting good at working on narcotic gases debate! It has been well hashed.
I'd rather we focus on how you find the depths at which we are affected (for the local conditions, activity level and good respiration rate).
Yes, plus the macho attitude that if you get narced you are a wimp.Maybe that is what fuels denial?
It would have been more accurate for me to say I'd rather skip the "you can work/dive just fine narc'd heavy/moderate/light" discussion. Working just fine because you breathe better, so have less CO2, so are not narc'd, is good to know.If I understand your intent, I don't know how to separate these two. The only way to discover your narcosis tolerance is to experience it, progressively and deliberately. Nitrogen narcosis is a very slow continuum, not a binary switch. The first step is learning the to deal with the second huge variable, CO2. You know the difference by deep and slow hyperventilation. The influence of CO2 goes away almost immediately. NN doesn't until you ascend. For me, hyperventilation is on the order of 6 to 8 breaths per minute — sort of like the beginning of a freediving breath-up.
It would have been more accurate for me to say I'd rather skip the "you can work/dive just fine narc'd heavy/moderate/light" discussion. Working just fine because you breathe better, so have less CO2, so are not narc'd, is good to know.
What about hanging at a depth for 5 minutes without He, seeing how you feel, then switching to He for 5 minutes and seeing if there is a difference? Then, if no difference, back to no He but breathing shallow, then switching to He and doing the same? So one depth, two different conditions of breathing, two gasses to see He effect.
Now, you could ascend for the lower END condition, but a gas switch would help keep the other variables the same, and better replicate the final condition of He at that depth, not staying higher on non-He. Which requires safe gas switches for that depth.
What about hanging at a depth for 5 minutes without He, seeing how you feel, then switching to He for 5 minutes and seeing if there is a difference? Then, if no difference, back to no He but breathing shallow, then switching to He and doing the same? So one depth, two different conditions of breathing, two gasses to see He effect. Which requires safe gas switches for that depth.
I have had the opportunity to dive air and HeO2 to the same depth up to 4 times per day, alternating air and mix on different dives. The depths were in the 165'/50M range and we were on open-circuit Scuba. It got to the point where we had trouble telling the difference between a mix and air dives except for being colder.
What about hanging at a depth for 5 minutes without He, seeing how you feel, then switching to He for 5 minutes and seeing if there is a difference? Then, if no difference, back to no He but breathing shallow, then switching to He and doing the same? So one depth, two different conditions of breathing, two gasses to see He effect.
Thanks. Hang was incomplete, again..., sorry. It would have been rather boring as well. Putter around the reef in that area would have been more accurate of my meaning. I would have at least been examining the environment around me and seeing if there was a difference in my awareness.If you want to determine the impact of narcosis, then you have to do things.
My intent is mostly around not diving on air, but on light trimix. But of understanding where that level of concern occurs for me and factors contributing to it. Not just papering over it with He. And this is all in the recreational range, for me.Learning to manage work load, breathing efficiency and remembering you are impaired at depth (in other words, second-guess and carefully consider all your decisions) are "skills" you need to develop to dive deeper on air (and hope to come up).
Maybe I need to take up macro photography, though invert surveys might have to suffice at first. My cautiousness on narcosis is from knowing I was confused by my computer in the past, in the 80-100' range.Marco photography can be very effective tool
Yes, which I read as highlighting breathing. And possible getting used to the task? Right, ok, so you really need a task. While at the 200' range breathing was not enough to prevent effects, but is well past rec range, though individual effects vary.Remember my story of repeatedly making dives on air and HeO2 at 165'/50M?
What comparison would I make between the two?I think a better experiment would be to do two dives, one on nitrox/air and one on mix.