A level is one depth held for one length of time. The planner’s Depth Profile section is a list of them, in the order you dive them: the only part of the plan that describes the dive itself rather than how it is executed.
Level 1
The fields
- Depth (m): the depth held, not an average and not a maximum excursion. The planner descends to it, holds it, and ascends from it.
- Bottom Time (min): time held at that depth, not a runtime. It starts when the descent reaches the level and stops when the ascent away from it begins.
- Label: optional free text, such as wreck bottom. It replaces “Level 1” as the card’s title and appears nowhere in the schedule.
A level can be added below or above an existing one. The remove control appears only once there is more than one level.
What bottom time excludes
Bottom time excludes the descent, the travel between levels, and the whole ascent: decompression stops, travel between stops, and the last stop to the surface. The number that includes all of it is runtime, reported on the Review step, which is why a 25-minute bottom time can produce a 70-minute dive.
Enter 30 minutes for a 30 m level and the planner holds that depth for 30 minutes. The descent at 20 m/min adds 1.5 minutes, so the ascent begins at runtime 31.5.
Multi-level dives
Levels are dived in the order they appear. The planner does not reorder them and does not require the profile to be monotonic: 45 m, up to 30 m for twenty minutes, then down again is a valid three-level plan.
Tissue loading carries forward across every level. A shallow second level is not a rest: the slow compartments keep on-gassing while the fast ones off-gas. The tissue view on the Review step shows it.
Next
Gas mixes is the next section down: what you breathe at those depths, and when you switch. Also worth reading: tissue compartments.