Brief hijack...
That being said when I dive I trust my buddy's computer (I haven't purchased my own just yet) and afterwards I do my tables just for the heck of it. More than once I have "been in deco" by the tables/eRDP and yet the computer still allows plenty of extra dive time, and its a Suunto!
2 Brief Comments and please, I'm not being critical, just hoping to provide a suggestion:
1 - I'd suggest that you shouldn't trust your buddy's computer - you and your buddy
may have materially different nitrogen loading depending on your relative position through a dive (e.g if you are slightly deeper than he/she for most of the dive, even a bit, the computer is not providing an accurate reflection of *your* profile.) you really should be diving your
own computer that goes where you go when you go. IMHO it is important and isn't a minor risk you may be taking.
2 Being "in deco" based on tables relative to a computer allowance is often the case if the dive profile you dive is not "square". This is one of the key advantages to diving a computer - irrespective of manufacturer. The tables work with a basic assumption/design that you go to your deepest depth and essentially spend your bottom time at that depth... in reality many (most?) dives don't go like that.
If you descend to, say, 40 feet to proceed to a wall, descend down the wall to 80 feet and spend the rest of the dive working your way back up slowly and when hitting the top at 40 feet make a leasurly return trip to your exit before beginning your direct ascent to the surface... the computer is constantly calculating the pressure you are under and the resulting impact to your thearetical nitrogen loading... the tables treat you as if you spent the entire bottom time at 80 feet. The computer gathers more information more often - so you are not treated as being under 80 feet of water pressure when you are only under 40 feet of water pressure... thus less nitrogen load... thus more dive time...
BUT - You cannot interpolate the tables - that is you
cannot simply say "well I didn't spend all that time at the deepest depth - so I'll just give myself less time, or drop a letter group, or anything else... If you are diving tables, you should really dive the tables. If you are managing your nitrogen loading using tables, then you should plan your dive and then dive your plan using the tables. Or invest in a computer of your own that will track your own experience. (No, I don't work for an equipment manufacturer, but I strongly recommend you have your own. Very functional, basic computers are continuing to drop in price - hopefully you can find one that meets your needs.)
again - not flaming, just a recommendation - "trusting" another's computer isn't really a safe diving practice. For those that may flame me - I know it *can* be done safely if ... (fill in conditions here).... , etc, etc, etc... But it still isn't a safe as having your own.
we now return you to your originally scheduled thread....
