Thanks for posting your results, Rich.  I too am interested in using Deco
Planner for shorter dives, and if the recommended deco times come out too
conservative.

Tod




kirvine@sa*.ne* wrote:

I think the problem is the dive is too short for the algorithm. JJ uses
helium based deco gas on the longer dives, and has told me that he
believes it shortens them but that the "formula" lengthes the short
dives. I don't use any softwware, and so do not know for sure. The
problem is that while JJ is attempting to get out something that
approximates the deco that we actually do, he and I really only do dives
that are pretty much off the scale in bottom time length to start with,
and the rules change markedly. The story there is that just to do a
normal cave dive in our systems implies bottom times approaching 100
minutes for everything at depths from 150 to 300, with a "norm" being
200 for 100, so again, what works does not always appear optimal for
short dives, but look at it this way: the big issue with me and JJ is to
get out of thes dives , and all dives , with no physical damage, so
while he and I may look like extreme weenies on a short dive deco-wise,
we look like crash test dummnies on a long dive, but both get out ready
to rock .

Just remember, phsyiologicly , helium is your friend, oxygen is yrou
enemy. Try to construct your deco so that the one decreases the need for
the other. Nitrogen is poison - and you need to be treated with oxygen
after you use it.

I copied this to techdiver since it is a great post by you , and will be
a question everyone asks. Thanks. I'd go right to JJ for more info. He
has put a lot into this, and he not only konws every thign I know, he
knows how to apply it to people other than the two of us.

DeepTrimix@ao*.co* wrote:
>
> George,
>
> I am going to go out on a limb now and see if, like any good neophyte, if I
> can recite back the information that I have learned in a cohesive, and
> hopefully coherent manner.
>
> Here goes...
>
> I purchased JJ's decompression software and ran a few of my "normal" type
> dives on it and then made the deco gas adjustments per your DIR suggestions.
>  When I changed my EAN50 deco gas to 50/50 the program delivered a
> substantial penalty.  Through the online discussions this was to be expected
> as a result of the Buhlman paradigm.
>
> My first leap off the cliff came in an assumption I made regarding the 50/50.
>  Since I am on my way up I am off gassing the Helium from the earlier portion
> of the dive so I no longer need to be as concerned with the ongassing in a
> deco bottle.  Is this a correct assumption or did I just kill myself?  Since
> the deco prgrams penalize me in all cases for having helium in my deco bottle
> I was not sure that this was a good assumption to make.  If I am wrong I am
> sure there are mistakes going forward.
>
> Anyway...
>
> Here is my attempt at a Buhlman (jj's decoplanner) vs. reality as I can
> interpret from the information that you have generously provided.
>
> The Dive   --   200'   25min   17/50
>
> JJ's decoplanner                                My attempt at Enlightenment
>
> 30FPM ascent                                    150-120 1minute each
> 110'     1                                      110'     1
> 100'     2                                      100'     1
> 90'       2                                     90'       1
> 80'       2                                     80'       1
> 70'       2 EAN50                               70'       4        50/50
> 60'       2                                     60'       1
> 50'       4                                     50'       2
> 40'       4                                     40'       2
> 30'       7 100                                 30'       5
> 20'       26                                        20'       13      100
>                                                 20'-0'     7
>
> Total dive 80                                   Total Dive 67
>
> I am trying to learn so if I got it wrong let me know.  I would rather die on
> paper than in the real world (it is much less permanent and painful on
> paper).  I am almost positive I missed something so please let me know.  If I
> am close I can email you the reasons why I made the decisions I did and maybe
> find the mistake.  If I am not even close I will scrap that math and start
> over.
>
> I really appreciate you taking the time to do this although I admit it is a
> bit painful to find out all of the things I learned over the past few years
> are... lets just call them misguided.
>
> Thanks Again,
>
> Rich


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