Posted by Karl S. on November 20, 2001 at 10:36:35:
In Reply to: Re: A few comments... posted by DougD on November 20, 2001 at 09:49:54:
Wayne's suggestions are excellent, Doug.
I myself always dive air tables using NitrOx, like Wayne suggested for safety, allowing the NitrOx as a margin.
It acts as a benefit in three major ways: first, it diffuses less N2 into your blood in the first place; second, it more quickly diffuses N2 out of your blood upon slow re-ascent; and third, the O2 diffused into your muscles is metabolized.
You just have to be careful to pay attention to the %CNS calculation for each dive and each repetitive dive.
The air tables that I have found to be my favorite are the Canadian DCIEM [Dept of Civil Institute & Environmental Medicine] because not only are they conservative like the PADI or the SSI recreational tables, and not only have they been Doppler tested like PADI, but the DCIEM tables also go down to 240 fsw and also contain decompression information!
Not that you should be diving to 240 fsw nor doing decompression dives. But when and if you graduate to technical diving, such as Stage Deco, NormOxic TriMix, and Hypoxic TriMix, the DCIEM tables come in quite nicely either as your primary source of decompression data or as your backup to your tech diving computer or your tech diving software.
I have been using the DCIEM tables as a primary source for dive planning for Stage Deco. Our dives in Stage Deco with TDI are to 150 fsw on EAN25 for 20 mins with EAN50 as the deco gas on reascent from 70 fsw.
Here is the EAN formula:
[ [ FN2 / 0.79 ] x [Depth + 33] ] - 33 fsw
Hope that whets your appetite a little for your next step: Advanced NitrOx.
You will learn lots of formulas in Advanced NitrOx. And the Advanced NitrOx cert card allows you to get NitrOx fills all the way up to pure O2 if you desire. This acts in effect as a personal "oxygen perscription" for yourself to be used in the case of decompression.
The DAN O2 Provider card is a license to administer O2 to another person in the time interval AFTER you have called 911 and BEFORE the EMS team arrives.
Oxygen is carefully controlled in California, unlike in some other states.
Flame me if Im wrong about anything, guys. Go for it!