The benefit of nitrox is the additional bottom time resulting from lower N2 content. period the end.
Since bottom time is N2 driven the less N2 in the gas the longer it takes to get full lof it.
The longer time can be used ONE of 2 ways.
1. you get to stay down longer before hitting your NDL
2. You comply with the NDL's set by higher N2 content gas ( air) and end the dive with less N2 in your system. This allows a shorter time for your surface Interval to purge the N2 from your system.
So you get your benefit on the bottom time end of the dive or the surface time interval end of the dive.
The decision involved is which end do you want it on. If you are making 1or 2 dives then use it on the frontend. If you are making many dives and depending on depth and you are ok with being limited by your buddies NDL then use it on the back end.
So on a set of dives your ndl's s are
air 14 20 25 25 26
nitriox 22 36 40 31 32
needed for the dive 17 19 25 27 30
use ean air air ean ean
making all dives ean ultimately would be the way to go for simplicity of legistics. If you dove ean and your buddy dove air you can see the time conflict because of the gas ndl's and or the lower end of day N2 level in you if you do not go to ean ndl's.
There is a lot of discussion on whether you have increased time physiology wise (not ndl) suing nitrox. I feel better and use less gas. Others see no difference. I strongly suspect that if there is s difference that it may be a health symptom. Perhaps smokers feel better ect.
I used to smoke fm 68-97. I suspect strongly that my longs do not function any where near capacity If you become winded easily then I believe you are not getting enough O2 in you. In that case higher O2 mixes could compensate for poorer lung effeciancy. Hgher O2 mixes lower respiration rates less gas used. I know many will argue it but that is how I react to ean30+ the same dive on air and ean 25 vs 36 min. 80 ft dives on ean 72 min vs 50 on air. sac high .4's to low .5's on ean and high .5's to mid .6's on air. That thought process may not be correct but the explanation works for me.
With out reading the dan article linked in another posting I would guess that a healthy, never smoker, may see no difference at all. So I sould say that ean does not add bottom time, but poor longs detract from bottom more severely on when on air.
Welcome back to the wet side.
Regards
Rather than hijack the "Who Offers Free Nitrox" thread, I thought I'd start another one.
I'd been away from diving for twenty years and just started diving again about four years ago. So I was out of the loop concerning dive computers (I now use one and love the added bottom time rather than the old PADI dive tables and "plan your dive and dive your plan" restriction) and now since diving in Cozumel, nitrox, which seems to be the latest thing.
So what are the benefits of diving nitrox?
How has it affected your diving?
Thanks for informing and old "newby"