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Doug, cut the crap, If you are going to talk about real dives you have to do
real dives. If you chose to begin counting your bottom when you step on the
boat, that's fine with me. If you want to use PADI OW rules for your diving
that's fine, too. If you chose to use an air computer for your dives and
wait out the computer so it won't beep at you all day, that is fine also.
You don't even have anecdotal evidence to the contrary. I have evidence
that it works. Try it sometime-EZ
>H2Ocaver wrote:
>>2)Bottom time starts when you hit the bottom and ends when you leave the
>bottom PERIOD.
>
>Pretty certain ("PERIOD")??? But wrong! Even your most basic PADI course
>instructs that bottom time is the time you leave the surface to the time
>you start an uninterrupted ascent to your first stop. If it becomes
>interrupted, then it becomes multi-level. Following generally recognized
>decompression theories (e.g. Buhlmann, Workman - the basis for many tables
>and computer programs) you will find their guidelines for constructing dive
>tables define bottom time in the same way. They also define an ascent rate
>which figures into the inert gas loading for computing an empirical
>decompression. It depends on how you wish to solve the differential
>equations (Workman has solved for a changing gradient on descent, but I
>believe the tables based on his work lump descent time with bottom time as
>well). Sure, there may be some statistical methods that may wish to define
>bottom time differently, but it would be interesting to understand how to
>account for descent time without solving or accounting for incremental gas
>loading during the descent or lumping it into the time on the bottom (for
>simplicity and margin). Case in point: On a 400ft dive, you take 4 minutes
>to make your descent, and then do a 20 minute time on the bottom. Are you
>saying the 4 minutes should be ignored and only the 20 minutes considerd?
>Not in my program. Gas loading is a function of a gradient and time of
>exposure, regardless of the type of gas. Hey I'm open for hearing relevant
>information about new and improved decompression theories.
>
>Take care,
>Doug
>
>
>
>
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