Posted by TDI_2 on June 14, 2002 at 09:15:59:
In Reply to: Re: because you need to relax more the deeper you go posted by Eric S on June 13, 2002 at 20:07:46:
I suppose PADI's strength lies in the vast research they have done on warm shallow water resort diving. PADI's parameters for diving seem to be centered on the maximum possible number of dives per day, I forgot how many, and maximum days in a row, three or four I believe, with a day of rest from diving every 4th or 5th day, I believe.
140 fsw in Cozumel is probably do-able with air. Out here in the cold North Pacific, where the water chills you, at least your hands and face with your drysuit, 140 on air is a serious nark dive.
GUE is certainly the most conservative agency when they (JJ and GI) say 100 fsw max on EAN 32, and then basic trimix from 101 to 185, and advaned trimix from 186 on.
TDI allows a custom nitrox mix to 150 fsw where EAN25 limits at that depth using a ppO2 of 1.4, then basic trimix to 185 fsw, and advanced trimix beyond 185. TDI also allows air to 185 fsw and basic trimix to 200 fsw, both for tech training purposes, but discourages it for real diving.
I cant speak for IANTD. I have read their manuals but not taken their courses.
NAUI leaves tech parameters up to the instructor, so it all depends if your NAUI tech instructor loves GUE [like Monsignor Tribes] or TDI more.
PADI is just now starting to go into "tech rec" so I can see why they cling to the notion that 140 fsw on air is safe. It is NOT. Anything over 100 fsw is an extreme dive and should not be done on air.