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jheimann%scsd.dnet@gt*.co* writes: > >You are lucky you did this. Computers continuously monitor time at depth, and >in this case would take into account the fact the most of your dive was shallow. >If it said you need to hang, then (at least according to the model used by the >computer) you did in fact need to hang. Unlike tables, computers don't assume >you have spent your entire bottom time at your maximum depth, which is why the >give you more bottom time than the analagous tables except for square profile >dives. The down side of this is that they are also less conservative than the >corresponding table, so If you blow off indicated decompression you are >taking a pretty big risk. Not to be a sourpuss, but I have to disagree with just about everything John claims. :( If your computer shows deco time at one point and not another, then you have simply offgassed below decompression between the two times. Theoretically, you need not take any stop. You are not taking any "big risk" by not remembering your max deco time and obeying it. Of course, you should take safety stops no matter what you do, whether you do pointless deep bounce dives or research dives to 60' on EANx. >Note that when people say that computers are more conservative than tables, what >they mean is that the Buhlmann algorithm on which most computers are based >is more conservative than the Navy algorithm on which the Navy tables are based. Not true, again. "Most" computers in the US are not based on the Buehlmann variations of the Haldanean model. I'd wager Oceanic and resellers sell more computers based on John Lewis' "algorithms" than do the "Buehlmann" resellers, at least in the US. (Add to that Orca's very large installed base.) The reason people say computers are more conservative than tables is that for a single square dive, computers based on the same model as a table will give shorter no-stop dive limits. This is simply because most computer manufacturers reduced the M-values over their table model, not because of anything related to Buehlmann vs. USN. Cheers, David Story NAUI AI Z9588, PADI DM 43922, EMT story@be*.wp*.sg*.co* Every dive is a decompression dive.
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