At 09:54 AM 9/24/99 -0400, Lee wrote: > >To continue the discussion, I have to move on to what I think about when >making decisions about my own diving. This is a different question, one I >have both a right and responsibility to answer. For context, I use the >strictest definition of reverse profile. I consider any dive that starts at >one level and includes descent to a deeper level part way into the dive and >any in a series of dives which is even an inch deeper than the previous dive >to be a reverse profile. In fact, that IS the definition used by Cochran's computers checking only the MAX depths to decide whether two profiles are "reverse" or not. THEREIN lies the PROBLEM of a well-defined definition that is truely ILL-DEFINED and ILL-TARGETED for the intended meaning of a "reverse profile" in the COMMONSENSE as well as scientific theory use of the that term. Dive 1. 1 minute at 61 ft. 59 minutes at 10 ft. Dive 2. 60 ft for 60 minutes. According to THAT definition, Dive 1 following Dive 2 would be a "reverse profile". I would rather think it's the OPPOSITE, in substance, theory, or commonsense. Your commonsense discussion (snipped) is indeed good commonsense. :-) >As additional comment, I agree with Bob's statements to the effect that >there are no conclusive scientific studies of reverse profiles and no I am not aware of the existence of ANY scientific study (involving DIVERS and SOME workable definition of a "reverse profile"). I'll be very glad to be told WRONG and pointed to ONE such study (done by a reasonably competent scientist -- just to cater to the possibility someone might say ... my high school psychology club did such as study! <G>) >knowledge, advise against reverse profiles predates my diving experience, >and I've been diving for a very long time. It certainly predates the multi >day, multi dive trips so common today and the very sophisticated (by the >standards of equipment I started with) dive computers. Especially MULTI-LEVEL dives in which (as in my examples (1) and (2) above) the MAX DEPTH is no longer a suitable indicator of the true nature of "depth" or "bubble formation". > Like "never hold your breath" and "always dive with >a buddy", this recommendation has grown beyond it's original significance >and context. In context, these are all good things to consider. Out of >context, they have little validity. But they are good material for flamewars! :-) >To head off the flames, I'l add a bit. (snip) I would just say to those inclined to engage in one of these "classic flamewars" to consult DejaNews first, to read even HALF of all the arguments PRO et CONTRA, and there wouldn't be any stern unstoned! :-) As Yogi would say, "it's deja vu all over again." :-) -- Bob.