well said!
The only thing I would add though is that as with beer some people can have 3 beers and you would NEVER know it while others are fine after three beers.
I have done some deep divs on air in warm water. In order to do this type of diving you have to work up to it. Just as if you drink all the time you are better able to handle drinking (you can not deny this). We all know people that can operate 100% fine at BAC .1 while others are falling all over themself. In fact when I used to drink a lot (way back) I could drink a lot more then I can now without getting sloppy and I have to say it takes a fraction of that now that I hardly ever drink. My friend, this is not just my perception it is reality there is tollerance to any narcotic.
Moral to the story: You can and will built a tollerance to any narcotic. I agree you will have the same amount in your body and BAC is simply how much you drink over time BUT the narcotic affect will differ based on your (you guessed it) Tollerance.
So while I have not been deep in a while if I dove down to 134' where PN2 is 4.0 (give or take) I would probably feel the effect and be impared. Now back a few years ago when I was going to 100-110 feet ever day or every other day I will bet that at a PN2 of 4.0 I was fine and NOT impared.
I agree with you last statement:
There's a difference between medical (and actual) "impairment" and the legal definition.
The only thing I would add though is that as with beer some people can have 3 beers and you would NEVER know it while others are fine after three beers.
I have done some deep divs on air in warm water. In order to do this type of diving you have to work up to it. Just as if you drink all the time you are better able to handle drinking (you can not deny this). We all know people that can operate 100% fine at BAC .1 while others are falling all over themself. In fact when I used to drink a lot (way back) I could drink a lot more then I can now without getting sloppy and I have to say it takes a fraction of that now that I hardly ever drink. My friend, this is not just my perception it is reality there is tollerance to any narcotic.
Moral to the story: You can and will built a tollerance to any narcotic. I agree you will have the same amount in your body and BAC is simply how much you drink over time BUT the narcotic affect will differ based on your (you guessed it) Tollerance.
So while I have not been deep in a while if I dove down to 134' where PN2 is 4.0 (give or take) I would probably feel the effect and be impared. Now back a few years ago when I was going to 100-110 feet ever day or every other day I will bet that at a PN2 of 4.0 I was fine and NOT impared.
I agree with you last statement:
There's a difference between medical (and actual) "impairment" and the legal definition.