You'll have to play with Gradient Factors. The algo is ZHL16-GF (OC or CC).
Basically, there are two numbers to play with: GF-Low and GF-High. It's often written GFxx-yy with xx being the Low value and yy the High value.
GF100-100 will give you a pure Bühlman decompression curve.
The lower the High value is, the longer the last deco stops will be.
The lower the Low value is, the deepest the first deco stop will be.
This is to go fast, you can find many papers on the theory behind this (on the Shearwater site for example).
GF are good to play with when doing O2 deco stops, it does not have a lot of sense using them with air only.
If you want to dive nitrox, you can use 85-85 as it will give you more security than a pure Bühlman deco curve while not extending stops too much.
You could play with a simulator (MV Plan for example) to see how those GF act.
Some articles on gradient factors:
Edited 1 time(s). Last edit at 12/12/2011 03:09PM by Stephane.