Dive planning with subsurface

[Pablo Wolter]

I don't know what algorithm NOAA uses on the table you are referring but
with adding a GF value different than 100/100 (which equals to a 100
Buhlmann or Workman M-value model) you are adding conservatism to your
profile, hence the deco stops.

Another thing to consider, what the algorithm you have in Subsurface and
the one on the tables. I guess is the same. I have not used SS to plan
dives, I can't understand the interface and haven't tried to either.

This is a really good paper by Dive Rite on GF:

http://www.diverite.com/education/rebreather/tips/gradient%20factors/

It helped me understand what I'm doing selecting different Low and High GF
on my decompression profiles. A good lecture too is Understanding M-values
by Erik Baker (you can google it for the PDF), so you will have a better
picture as to what and why on each profile changes depending on your
selections.

Just my 2 cents on what I know. If you can share the table you are using I
would be able to see what the models differences are.

*
*
*Saludos,*
*
Pablo Wolter
pwolter at gmail.com

*


On Fri, Oct 11, 2013 at 3:51 AM, Willem Ferguson <
willemferguson at zoology.up.ac.za> wrote:

> I am trying to get to grips with some of the more technical dive planning
> features of subsurface.
>
> Doing a dive using the NOAA no-compression Air table, I should be able to
> dive to 34m for 20 minutes and return to the surface without a deco stop. I
> set the GF at 40/80 and now plan this dive using the dive planner, enabling
> the ceiling calculations. What happens now is that the dive becomes a deco
> dive with three deco stops, starting at 9m, because the ceiling does not
> allow me to surface safely. See screen dump:
> https://www.dropbox.com/s/**7by4ecqjwgr6f13/PlanDiag1.png<https://www.dropbox.com/s/7by4ecqjwgr6f13/PlanDiag1.png>
>
> The data for the dive are very simple:
> GF40/80
> 34m  +3 min
> 34m  +20 min
>
> What am I missing?
> Kind regards, Willem
> ______________________________**_________________
> subsurface mailing list
> subsurface at hohndel.org
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>
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