The Tissue Saturation view is the answer to “why is the first stop there”. It plots the model’s own compartments across the whole dive: sixteen under Bühlmann, drawn against the gradient factors the plan was computed with, or the parameter set’s three, five or nine under Thalmann, drawn against the model’s own tension limits. The same map appears in the plan report.
Reading it
- GF % trace: the sparkline across the top follows the leading compartment’s gradient-factor percentage, with dashed reference lines at your GF Low and GF High (Lo and Hi) and a faint line at 100 %, the model’s unmodified limit. On a Thalmann plan the trace reads Limit % instead: the same quantity measured against the model’s own permissible tension, with no Lo or Hi lines, because gradient factors play no part in a Thalmann ascent.
- Heat map: one row per compartment, fastest at the top, one column per moment. Under Bühlmann that is C1 (5-minute half-time) down to C16 (635 minutes); under Thalmann the rows are the parameter set’s own, C1 (5 minutes) to C9 (240 minutes) on VVal-79. Read a row left to right to watch one compartment load and unload.
- Leading trail: a pale dotted line marking the compartment closest to its limit, the one setting the ceiling. Which one that is changes hands as the dive runs.
- Elapsed minutes run along the foot.
Hover for the time and depth, the leading compartment and its half-time, its saturation, and its GF % (Limit % on a Thalmann plan). A negative value means the compartment holds less inert gas than the pressure it is under: still on-gassing.
The colour scale
Cell colour is saturation: the compartment’s loading as a percentage of the most the model lets it hold at that depth. The ramp is continuous between these points:
- 0 to 25 %: deep navy, barely distinct from the background.
- 25 to 55 %: navy brightening to blue. Loading, well clear of the limit.
- 55 to 80 %: blue warming to amber. Elevated.
- 80 to 100 %: amber deepening to red; 100 % is exactly on the limit.
- Over 100 %: solid red, past the limit the model draws.
Cells grow more opaque as they load, so quiet rows recede. Three patterns:
- On descent the top rows warm within minutes while the bottom rows stay dark: fast compartments fill first.
- On ascent the top rows cool first while the slow rows are still warming and peak at the shallow stops. That handover is why lowering GF High costs so much more time than lowering GF Low.
- On a multi-level dive a shallow second level shows both at once: fast rows cooling at 20 m, slow rows still loading.
What to watch for
- Under Thalmann E-L the map is the model’s own picture: each row is measured against the maximum permissible tissue tension its parameter set allows at that depth, the same limit that draws the stops. At 100 % the compartment sits exactly on the line that pins the ceiling. The trace reads Limit % and carries no Lo or Hi lines, since gradient factors play no part in a Thalmann ascent. See Decompression models.
- On a rebreather the graph follows the bailout selection: tissue state to the bail point comes from the loop dive, and everything after it is that scenario’s open-circuit schedule.
Next
The models view is the last of the five. Tissue compartments covers what a compartment is and why each model carries the number it does.