Personal Dive Tables

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Even though i am GUE-trained (Tech1), i first heard about variation of deco-on the fly from my TDI instructor, also known as Doppler on this Board

:)

There is nothing "rocket-scientific" about it - you just learn the face of the algorithm of the program that you trust and then are able to modify it on the fly as required. Doppler uses V-Planner and GUE uses Decoplaner with tweaked GFs, although i am hearing the new deco planner will be a VPM-B based (i.e. same model as V-Planner)

The funny thing is that for shallow (150ft -/+ 30ft) deco diving, the GUE's Ratio Deco produces the deco table that matches V-Planner with conservatism factor of 2 to almost to a min in terms of total time, so i only have to know one algorithm

:)
 
Manos once bubbled...
The are three level of the so called "teckies" :

1: the ones that rely on their computers for deco , and then the get bend once it fails.

2: The divers that print tables from a program and keep in thair pockets ( nothing wrong with that ).

3: The divers that understand decompresion and can calculate deco " on the fly "


Cuting your tables is not a big deal , you dont need to be a phd math professor.

Go and search about GUE and learn what is " deco on the fly "

Dont spread it arount cause the whole story upsets the VR3 divers.

For brevity as well as completeness I would suggest combining Group #1 and Group #3 into the same group. :)
 
IndigoBlue once bubbled...


For brevity as well as completeness I would suggest combining Group #1 and Group #3 into the same group. :)

Chortle. Now the Amish Diving Society boys are going to have to reply and pretty soon all hell's gonna break loose. :fork:
 
:D Here's a "heads up" to Heads Up,...it truly is NOT a simple subject, but there ARE ways to simplify the application of it!:D

To break it down somewhat, it is good to look at it from a basic perspective.

The deco programs in use are (1) Haldane-based (or neo-Haldanian, as Charlie pointed out), and (2) non-Haldanian.

Most of the popular, (here read prevalent), programs are directly based on Haldane's work, with added modifications, or "tweaks", and thus can be labled "Neo-Haldanian". As such, they deal with gas as it moves into and out of solution.

A real argument begins when you get to the non-Haldanian category. It could be argued that any time you deal with gas in solution in the body, you are dealing with a subject researched and more or less "codified" by Haldane. Therefore, in the strictest terms, all of the newer work is at least neo-Haldanian. Now, of course, it can and will be argued by the mathematicians and physicists that the mathematical model is completely different, and therefore the previous statement is not correct. I would have to venture that this would be a subject for them to argue. For the rest of us, it does not matter a heck of a lot!

What does matter to us is ease of use, and the general level of safety in the practical application, i.e. our diving. We as divers must recognize that NOT ONE of these programs can offer a 100% guarantee of safety. If nothing else, that is not statistically possible.

It then behooves us to find a model that has been well researched, both mathematically, and physically.

A good example is the Reduced Gradient Bubble Model (RGBM), created by Dr. Bruce Wienke, of Los Alamos National Laboratory (LANL). RGBM is a deco model that treats both gas in solution, and gas in the free or bubble phase.

Dr. Wienke is, in actual fact, a nuclear physicist. He is also a diver, and an advisor to various government special operations dive units.

Dr. Wienke has put his model through rigorous mathematical testing, using the super-computers available to him at LANL. (I would venture to say LANL has at least as much computing power available as the NSA (No Such Agency), and perhaps more so.

The model has also been rigorously tested by human "crash test dummy volunteers" from various government dive groups, Tim O'Leary's NAUI tech research folks, IANTD's Tom Mount, and others, and has proved to be extremely successful.

It has been suggested to me, by certain individuals in the profession who should know, that the latest iteration of the "GAP" by Kees Hofwegen, is the best example of a full-implementation RGBM program currently available. I do know that the "GAP" has a good user interface, and seems to be relatively intuitive to use. It also offers a fair amount of user adjustable factors to account for such things as workload, temperature, and user preference (i.e. diver desired level of "conservatism").

For an excellent treatment of the subject of decompression and of the RGBM, I would recommend the book "Technical Diving in Depth" by B. R. Wienke, offered by Best Publishing. I would be the first one to admit that I am not a mathematician, either by trade or preference. There is, however, enough explanation in the text to enable one to "read around" the math and understand what has been done with the concept. For those so trained and inclined, Dr. Wienke has included the math as "proof of concept".

I hope that this will be helpful to you in your understanding of a sometimes nebulous and often confusing subject! :rolleyes:

BJD
 
vlada once bubbled...
Even though i am GUE-trained (Tech1), i first heard about variation of deco-on the fly from my TDI instructor, also known as Doppler on this Board
Doppler has also contributed a very good article to the deco stop's public section, which discusses how he calculates deco. While not 100% complete, there is enough there to be a good guide to someone going down that path.

Charlie
 
If you are geek enough to read (without falling asleep) Wienke then "RGBM In Depth" is another good one.

You didn't find the good deco post by searching under GUE because it is on the WKKP page;
http://www.wkpp.org/decompression.htm

There really is more to it than George covers on that page but there are lots of good points in there.

If you do deco diving long enough (or even NDL diving) you are at pretty good risk of getting bent. Accept it and know where the nearest chamber is and how long it will take to get there. If the travel time is long, that is more than an hour or so, you might want to investigate in water recompression IWR. For a good start read;
http://www.bishopmuseum.org/research/treks/palautz97/iwr.html

Proof of all of this stuff is left as an excersize for the student. :D
 
BigJetDriver69 once bubbled...
[B...

A good example is the Reduced Gradient Bubble Model (RGBM), created by Dr. Bruce Wienke, of Los Alamos National Laboratory (LANL). RGBM is a deco model that treats both gas in solution, and gas in the free or bubble phase.

Dr. Wienke is, in actual fact, a nuclear physicist. He is also a diver, and an advisor to various government special operations dive units.

Dr. Wienke has put his model through rigorous mathematical testing, using the super-computers available to him at LANL. (I would venture to say LANL has at least as much computing power available as the NSA (No Such Agency), and perhaps more so.

The model has also been rigorously tested by human "crash test dummy volunteers" from various government dive groups, Tim O'Leary's NAUI tech research folks, IANTD's Tom Mount, and others, and has proved to be extremely successful.
...
BJD [/B]

My copy of BRW's new RGBM tables came in the mail yesterday. I read through them last night.

Here are my questions:

1) Why no lean deco mix on any of the new RGBM tables? The tables indicate deco on bottom mix all the way back to 20 ft, then switch to 100% O2 at 20 ft for the 20 and 10 ft stops. I am very surprised that nowhere in these tables, for Air, Nitrox, nor Trimix is there ever any lean deco mix such as EAN50 or EAN40 prescribed.

2) What if I use EAN40 for all of the deco stops from 100 ft to 30 ft? Is there any problem with that?

3) The TMX 10/60 tables implicitly require a travel mix. Is the 100% O2 to be used as travel mix to 20 ft? Or would you sling another travel mix instead? I would normally use lean deco mix for my travel mix, but there is no lean deco mix for the new RGBM tables.

4) Since 100% O2 is used at the 20 ft and 10 ft stops, I presume that also requires 5 min air breaks after every 15 mins on O2?

5) Can all of the 20 ft and 10 ft deco time be combined an spent at 20 ft as well since 100% O2 is being used?

Does anyone know the answers to these questions?
 
Indigo,

I sent your questions off to BRW, but he may be off on one of his periodic jaunts for "Uncle".

A good man to talk to in the "horse's mouth" category would be Tim O'Leary. Contact him at the "American Diving Technical Dive Center".

website: <www.divesouthpadre.com>

BJD
 
Well the WKPP stuff doesn't add much only a few laughs at GI's typing and the use of the word bull**** to add weight to reasoned well-balanced debate....

I did however find an old BBS posting by Bruce that gives some better background. It is hard going, so I guess I need to buy the book..

I can see that an ability to figure out a deco when things go wrong would be a very useful thing. I don't now think that's what I am going to find. Thanks to everyone for the links though it has been interesting reading.

Chris.
 
http://cavediveflorida.com/Rum_House.htm

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