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> Without facts, I prefer to keep using field tested deco tables for both 
> air and trimix dive during cave diving.
> Thanks for the coming info...

Certainly, MiG Plan uses an unmodified Buhlmann algorithm, so all of the
testing used to validate his tables applies also to MiG Plan.  You could
also say that the experience with his published tables, and to a lesser
extent the experience with the Aladin Pro computer (it's a slightly
different and more conservative model) is also valid for MiG Plan.  

On the other hand, there is little offical testing of the Buhlmann model 
as it is implemented for Tri-Mix.  Certainly it seems to work well in the 
many technical dives that have been made using MiG Plan and other products, 
but there is little official testing.

Because we do not have the resources to conduct full scale testing (as is 
the case for all other desktop decompression software packages to my
knowledge) we have chosen not to modify the model.  Some of the other 
packages make changes to try to make the model more conservative.  Some 
of these changes are safe and reasonable, but some are potentially 
hazerdous.

For example, I understand that some programs artificially add extra
minutes to the bottom time you tell them.  This could be dangerous in a
multi-level dive becuase if the diver comes up to a shallow depth where he
is actually outgassing from some tissues, the model may think the diver
has outgassed more than he actually has, potentially leading to a hit. 

The obvious way around this problem is only add minutes to the deepest 
depth of the dive; but this means that multi-level dives get a smaller 
safety factor added to them.  This is a bad idea, because if you are 
trying to add safety, you want to do it in a way that that yields both a 
consistant safety factor, and cannot make the table more dangerous.

MiG Plan does allow the user to add a bias factor to produce more 
conservative tables, but it is used to directly reduce the "M" values in 
the model, which is an accepted way of making tables safer in a consitant 
way without producing side effects.  You might think of this as simliar 
to telling the model that the diver is diving at altitude; the model is 
unchanged, but becomes more conservative.  

   Jody Svendsen
   MiG Technologies

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