Breathing rates

The Work Rates section: working and decompression consumption, the bailout pair a rebreather plan adds, and the reserve rule each cylinder is held to.

The Breathing Rates card opens the Work Rates section of the Plan step. It holds two fields on an open-circuit plan; a rebreather plan adds a second pair, covered below.

The rates a new plan starts at, 15 L/min working and 12 L/min on the stops

Working SAC (L/min)

Deco SAC (L/min)

The two fields

Working SAC (L/min): charged for the descent, bottom time, travel between levels, and every part of the ascent that is not a stop. The planner starts at 15 L/min.
Deco SAC (L/min): charged for mandatory decompression stops, where you are hanging rather than swimming. The planner starts at 12 L/min.

Both accept 5 to 40 L/min, in steps of 0.5.

Neither rate touches the schedule: depths, stop lengths, runtime and time to surface (TTS) are identical whatever you enter. What changes is every gas figure that follows: the volume used per gas, the pressure remaining in each cylinder, the reserve, and the turn pressure. Set them before you read the Gas Consumption view.

The bailout pair on a rebreather

A closed-circuit plan keeps both fields, retitled Open-Circuit Breathing Rates, and they still describe your open-circuit breathing. On top of them it adds a Bailout Breathing Rates card in the same section:

Bailout Working SAC (L/min): charged from the bail point until the settling window below has elapsed. The planner starts at 50 L/min.
Bailout Deco SAC (L/min): charged from there to the surface, the ascents between stops included. The planner starts at 25 L/min.
Settling Window (min): how long the working rate is held after the first decompression stop is reached. The planner starts at 10 minutes.

The rates accept 5 to 60 L/min and are higher than the loop figures on purpose: a diver who has just come off the loop is a diver who has just had a problem. Leave either blank and the plan’s ordinary working and deco rates are used in its place.

The settling window is measured from the moment the first stop is reached, not from the start of the ascent, so on a stop held longer than the window the changeover falls part-way through it and that stop is billed at both rates. Set the window to 0 and the bailout is billed the way a planned open-circuit ascent is: the deco rate from the moment you arrive. A planned ascent never gets a settling window of its own.

The rates on this page account for open-circuit gas only, whichever mode you are in. The loop’s own oxygen is budgeted from the workload set on the Metabolic Oxygen card in this section, not from a SAC rate.

Reserve rules

The Reserve Rules card, below the rates, sets the rule each cylinder’s reserve is held to. One rule per gas role: Back gas, Stage, Deco, and Bailout on a plan that carries a bailout cylinder or a loop. A role you never touch keeps Thirds.

Thirds: a third of the starting pressure, the rule every role starts on.
Halves: half of the starting pressure.
Minimum gas: an emergency ascent reserve, computed at a stressed breathing rate. Stress SAC x scales the rate, starting at 1.5; set Team divers to 2 and the cylinder is sized to bring the whole buddy pair up.
Fixed bar: a pressure you name.
None: no reserve held back. An explicit choice, never a default.

Reserves are reporting only. Changing a rule moves the Reserve and Turn pressure figures in the Gas Consumption view and the labels that depend on them; the schedule itself never changes.

Decompression settings is the next section: the model that shapes the ascent, and how conservative it runs.