Posted by John Walker on February 10, 2001 at 11:31:32:
In Reply to: You just can't take a hint posted by seahunt on February 07, 2001 at 21:07:18:
Speaking of a blustering Santa Ana winds, I did read through your post. You obviously have a lot of free time on your hand. A lot more than I do. It appears that you site around and make such long winded replies in order to convolute any sense of the matter in hand. Would this be the case?
You continuously attach DIR, deep diving,wreck diving, cave diving in your replies to me but I rarely mention any of them other than Nitrox. When I do its only in direct response to questions asked of me. I realize this is a recreational list and I choose not to advocate dives that are beyond this groups ability to comprehend. It is my feeling that you attach all of these names to me for some other reason. Possibly because others have made reference to me doing dive other than what most of you do.
The issue I have with you is about nothing other than SAFETY. You have the ability to influence divers. Divers read your long winded post which give an appearance that you advocate dangerous practices which have been attached to diver fatalities. That it!
As for your attachmant of MHK's rebuttle. What does that have to do with me? What I get out of it is that none of you can even understand what a dive table is. Hell, now days organizations don't even teach them. Computer education is what you get from some courses. The problem is that computers are a reference and thats it. But it is installed in divers that:
1) if you stay within your no decom limit you are safe
2) if you exceed your no decom limit you will get bent
A historical outlook in decompression modeling is very important in order to have a half ass clue as to what you might be doing to you body on a dive. Often when one learns a certain amount of the diffused gas theory and bubble mechanics they realize that there is no way a computer is going to be able to tell you just what is going on inside of you. So they learn things that help them make there own decompression stratagies like:
1) the shapes of profiles
dissolved gas theory
m-value
variable permiability models
Reduced Bubble Gradient Models (a
combination of a couple others)
these all creat diffewrent shapes to a
decompression curve. They can all vary a
lot as far as time spent getting out of the
water as well
2) other factors such as
j-factors (fat content)
gas selection
workload
physical condition
hydration
The problem with that is that decompression modeling is much more complicated than these computers are. Diver education has become so heavily distilled of actual pertinent information that most never get a clue unless they seek out imformation through means other than you typical diver training. These computers have the ability to hurt divers who put trust in them. They default if your ascent rate changes slightly and tack on unnessesary decompression obligations, often when a diver has limited gas supply to complete the obligations that the computer is giving them. They are most often based off the archaic Bulhmann algoritm which has proven its self unreliable so some are tweeking the gradient factors of its m-value which is putting it a little closer to a bubble mechanic profle which generally gets better doppler results.
And in order for you to go out and compute on the fly you need to have a basic understanding of decompression theory. And my guess is that there are only a hand full of people on this list who do have that basic understanding.
Furthermore, this list is not the proper podium to teach such a topic. It is a terrible medium for communoication of such complex subjects. Its like teaching calculus before basic math skills are aquired.
If my spelling is bad, live with it. Its probably not going to kill you.
JW