// ~/playground/bent

Bent

Get bent

Type one dive. Get that dive, the deeper and longer versions of it and, on a rebreather, the bailout for every one of them, side by side. Then lay any three on one chart and see what a minute or ten feet costs.

Experimental and still under development. Do not plan a real dive with it. The VPM-B model is a port of Erik Baker's published program and is checked against it, repetitive dives included. Beyond that the checks cover only a narrow range of dives, and passing them does not make a plan safe. Read it, argue with it, and check anything it tells you against a planner you already trust.

$ ./bent --plan # numbers in, everything below follows

Breathing

Model

Depth in

Pressure in

Gas in

Depth

Bottom time

min

Diluent

Setpoint

PO2

Gradient factors

low

high

Conservatism

Bailed out

Bailout gases

O2 %	He %	Switch at	Cylinder

More levels

Levels after the first, in order. A level's time counts from leaving the one before, so it includes the swim. The grid's deeper and longer steps apply to the first level.

Earlier dives today

Dives before this one, in order, each flown with the settings on this page. "Then up for" is the time at the surface before the next dive. Everything below is then the next dive of the day.

Rates, water, breathing rates, stops, setpoint changes

Descent

Ascent

Between stops

Last ascent

Last stop

Water

Water vapour in the lungs

Coefficients

First stop

Stop times

Breathing, bottom

Breathing, deco

Breathing, bailed out

Going down, the loop is at

PO2

Where the diluent is richer than the setpoint

Setpoint on the way up

PO2

Gas switches, warning limits, narcosis

Switch PO2, 45% and up

PO2

Switch PO2, 28 to 45%

PO2

Switch PO2, under 28%

PO2

Oxygen no deeper than

Last stop, bailed out

Flag CNS over

Flag OTU over

OTU

Note a switch over, bar

N2↑

He↑

Narcotic gases

$ ./bent --contingencies # the same dive, deeper and longer

Deeper by

Longer by

min

Each cell shows

—

Bailout gas, worst cell on the grid

Gas	Needed	Worst cell	In the cylinder

Gas volumes are surface volume at the bailed-out breathing rate for the whole ascent, with nothing held in reserve. Cylinder pressures treat the gas as ideal, which flatters helium mixes at high pressure.

$ ./bent --overlay # up to three profiles on one chart

Pick cells in the grid. Pin one, change the setpoint or the gradient factors, and the pinned profile stays put for comparison.

$ cd .. → more interactives