A decompression model is a set of rules for predicting how much inert gas your tissues hold at any moment, and how shallow you may be before that loading passes a limit the model treats as tolerable. Every schedule DiveLogic produces is one model’s answer, and different models answer differently for the same dive.
The Algorithm field on the planner’s Plan step offers three entries. Two are complete models; the third translates one into the other.
What each entry is
| Entry | What it decides | When a diver would pick it |
|---|---|---|
| Bühlmann ZHL-16C | Your ceiling from tissue loading, with gradient factors setting the margin | The default, and what nearly every dive computer runs. |
| Thalmann E-L | Your ceiling from a fixed off-gassing assumption, with no conservatism control | Comparison and research; each parameter set applies only to the diving it was fitted to. |
| Thalmann GF Calibration | Runs Thalmann as a reference, then reports the gradient-factor pair that comes closest to it | When you want a Thalmann result expressed in the vocabulary your dive computer uses. |
Selecting Thalmann or GF Calibration also reveals a Parameter Set field. Both entries use those sets; Bühlmann does not. Read the Thalmann page before relying on any of them.
What choosing a model does not do
Changing the algorithm changes the schedule, not the dive. Gas density, oxygen exposure, narcosis, thermal stress and exertion are the same whichever model produced the stops, and none of them is modelled by any of these entries. A model that returns a shorter runtime has made a different assumption, not a safer dive.
Nor is a model a probability. No entry returns a chance of decompression sickness.
Next
- Bühlmann ZHL-16C, the default model.
- Decompression settings, where the algorithm is set.