Posted by Maddiver on November 19, 2001 at 00:07:42:
In Reply to: Re: More thoughts on NitrOx posted by Karl S. on November 18, 2001 at 17:55:48:
Karl-
Glad to see your logic and reasoning taking form. I agree with much of what has been said in these posts and share the personal thought that Nitrox does best when taught early (ie ow class extra session(s)). The point that your class/instructor may have neglected is the difference between END, END, and EAD (yep that's two END's) equivalent nitrogen depth and equivalent narcotic depth (and of course equivalent air depth but everyone seems to be on the same page when discussing EAD's). Point is that many experts today see addition (or the very presence) of oxygen to be **atleast** as narcotic as nitrogen in the breathing gas. So in essence if you subscribe to this theory (and most of the really heavy experts Hamilton, Weinke etc do believe it has merit) then you see the difference in calculating END vs END vs EAD in essence 'Narcotic Depth' really now has two factors nitrogen and oxygen. This needs to be taken into account on a 25% nitrox dive to 150. In fact your END (narcotic) is greater than what you think it may be if you give yourself 'credit' for the additional O2 in the breathing gas. This is not intended as a 'Flame' but a clarification on a few points that many Trimix instructors still are coming to grips with. The 'empiracle testing' many may cry for may be impossible with human subjects due to the CNS toxicity issue (ie how do you test a human's performance under increased O2 when you subject them to higher levels and they have seisures? However there is evidence on the molecular/cellular level and ***Isn't better to error on the side of conservatism until we do have 'empiracle human evidence'.