Posted by Kendall Raine on March 05, 2001 at 09:28:26:
In Reply to: Fabulous Presentation: posted by mattschechter on March 03, 2001 at 21:38:42:
I'm glad the presentation was so positive and productive for you. Your post shows you were listening and that you get it. You're right, DIR is a philosophy of diving with the equipment and standardization flowing from the philosophy. The equipment is secondary. Without the philosophy really understood, the equipment and its standardization seem arbitrarily rigid. I think it also goes to show the limitations of trying to discuss controversial subjects over the internet...
I have a few thoughts about your post; however.
1) Computers. You're right, JJ has nothing per se against computers. His gripe is that using a computer as a substitute for knowledge of decompression principles and awareness of what's going on in your own body is a bad thing. Carried further, only listening to what the computer is telling you is surrendering to a model which has less and less to do with what is really going on in your body as the dive day wears on. JJ discussed the limitations of the Haldanean and neo-Haldanean models employed in most dive computers. That is, they only focus on dissolved gas phase issues while largely ignoring free phase bubble mechanics. As such, they tend to bring you up too quickly and then try to compensate by having you hang out at the shallow stops-even DAN now recognises this. Hence, the old algorithms are wrong. This of course is not addressed in the users' manual to the computer except implicitly in the liability warnings in the back. Finally, computers are a one size fits all solution. Someone who has 30% body fat, lousy aerobic shape and 70lbs overweight who uses a computer is running the same NDL/deco profile as someone with 7% body fat and trains regularly. Are their bodies filtering inert gasses with the same efficiency all other things equal? No way. The computer doesn't know the difference; however. The only way the fat guy doesn't get bent is if the computer is very conservative. It is. Similarly, the computer doesn't know if you had a lousy night's sleep, feel seasick, dehydrated or just a little off. The point is decompression (every dive is really a decompression dive) is very personal and computers are by definition impersonal. That's why JJ views computers as a training device from which an informed diver will eventually seek to ween himself.
2)You say that you thought from reading the internet that DIR was "non-changeable, rigid, hard-assed...It is not." Don't be fooled by the fact that JJ is a moderate, well spoken nice guy. Actually, DIR is quite rigid inasmuch as the equipment layout is quite standardized. It does not contemplate personal modifications and, in fact, is designed to work as a unified whole. I think you were referring to such things as no requirement to use a long hose in OW. Absolutely. While many people who dive DIR in OE chose to keep the long hose in OW, the real purpose of the long hose is to accomodate tandem swimming in an OOA situation. The notion that one must use a long hose in OW came from those who don't understand the system, not from those who dive DIR.
DIR is dynamic in that it seeks to evolve. Once a new idea is adopted; however, the modification becomes part of the system and is not unilaterally changeable. Unilateral changes are viewed as not DIR and a threat to the effectiveness of the whole configuration. The direction of evolution is effectively controlled by a few people in the WKPP. This centralization makes many people uncomfortable. I would suggest that before deciding whether the notion of a unified configuration makes someone uncomfortable, they at least take the time to really investigate what's behind it before rejecting it. If then it still doesn't feel right, so be it. The problem, it seems to me, is that many detractors are half-informed about DIR and that they're rejecting it out of emotion rather than reason.
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