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on 26/5/01 4:55 AM, Jim Cobb at cobber@ci*.co* wrote: > Tom, look if you are asking if I sit on the hang line and say "hey, wonde= r I > I'd get bent if I surface now". Or "hey, I didn't get bent on that last > dive, think I'll crank the gradient all the way to the other side and see= if > I get bent then". >=20 > No, that's not what I do. You are being a bit churlish here, aren't you? = You > start with the default of the tables program you are using and see how yo= u > feel. Feeling a bit tired after the dive? Not quite right? Then modify th= e > gradient, start the stops a little deeper, stay on the 02 a little longer= .. >=20 > You do the dive and feel fine? Great. Crank back on the gradient a little > and see what the effect is on your deco time and do the dive. Then see ho= w > you feel. For most people you will be doing this continuously during your > diving career. Jim, just to let you you know that even newbie gumbies like me are "getting it" and please keep up the lack of tolerance for stuff that doesn't make sense, no matter who it is. Guys new to tech diving (like me) need the guys like you and Billy. >> From: "Tom Mount" <TOM.MOUNT@in*.at*.ne*> >> Third: You stated you deliberately bend yourself then back off. Now that >> cannot be considered a logical or intelligent action. I have clipped some pieces from the following article I read last week. You may note that the authors have a been known to have a reasonable grasp of deco theory and application ;-) and (IMHO) seem reasonably logical and intelligent. From a paper called: Implications of the Varying Permeability Model for Reverse Dive Profiles Authors: David E. Yount, Eric B. Maiken, Erik C. Baker > The first reason why some technical divers prefer to design and test thei= r own > tables is that they can. Many have computational abilities that far excee= d > those of > decompression pioneers, who produced operational tables in an era when th= e > physics of bubble formation in aqueous media was poorly understood, and > commercial decompression programs, dive computers, personal computers, an= d > powerful software did not exist. The second reason technical divers might > choose to design their own tables is that they have easy access to > unconventional algorithms, such as the Thermodynamic Model (Hills 1966), = the > Varying Permeability Model (Yount and Hoffman 1986), and the > Reduced Gradient Bubble Model (Wienke 1991). By =B3easy access=B2 we mean tha= t > they have both the mathematical skills needed to understand these publish= ed > algorithms and the computational skills needed to implement them, if need= be, > from scratch. The third reason is that many technical divers are dissatis= fied > with the results of conventional > algorithms. There is also widespread suspicion that something is missing,= that > there is a need for =B3deep stops=B2 as called for by LeMessurier and Hills > (1965), by Yount and Strauss (1976), by Hennessy and Hempleman (1977), an= d by > others. and a little further in that paper: > So what we have here is a new paradigm in which a technical diver modifie= s an > existing table, tries it out on himself, and decides to keep or reject th= e > modification to his diving practice on the basis of how he =B3feels.=B2 While= more > subjective than the usual method of =B3titrating=B2 Navy divers five at a tim= e, > this empirical, try-it-out-on-yourself method is actually far more sensit= ive > because it replaces the bimodal endpoint of bends/no-bends with > a conti= nuous > scale that associates greater comfort with greater safety. It is importan= t to > note that these divers often have personal experience with a full range o= f dcs > symptoms, and are therefore discerning observers. What they are saying here is just so common sense. There is no line between "bent" and "not bent" (Duh!) it's more like: Not Bent----------> Increasingly graduated deco stress ----------> Bent What I believe Jim (and the above paper) is suggesting is possible, is to start at the extreme left of that scale and work your way incrementally to the right, listening to your body. The feedback comes in working from the NOT BENT end of the scale and using the deco stress (not DCS !) as feedback= .. This is just so "right" how can anyone NOT get it ? Everyone is different, each person's body reacts just that much differently to the stresses of a dive. How can a bit of silicon and plastic manufactured halfway round the world, strapped to your arm, that doesn't know anything about your body do better than that ? regards *** dean laffan real world productions melbourne, australia ph +613-9419-3966 Mobile - 0418-525-315 It said on the box: 'Requires Windows 95 or better' ... so I bought a Mac ! regards *** dean laffan real world productions melbourne, australia ph +613-9419-3966 Mobile - 0418-525-315 It said on the box: 'Requires Windows 95 or better' ... so I bought a Mac ! -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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