www.chromatography.co.uk/Techniqs/Other/Pressure.htm

1bar  is 15 psi (or 14.7 to be perfect)

PRESSURE:

1 atm = 14.7 psi = 1.03 kilograms per square centimeter = 1 bar

1 deg F makes a 5 psi (approx.) change in pressure in a SCUBA tank.

Airplane cabin pressure @ 30,000 ft = atm @ 8000 ft = 10.5 psi (approx.)

In salt water: (Depth in feet)

atm = Depth / 33

ata = (Depth / 33) + 1

psi = Depth x 0.445

psia = (Depth x 0.445) + 14.7

In fresh water: (Depth in feet)

atm = Depth / 34

ata = (Depth / 34) + 1

psi = Depth x 0.432

psia = (Depth x 0.432) + 14.7


About 675 feet in saltwater, 700 feet in freshwater

Every 100 feet is 3 bar.  give or take.

Quoted: Every 100 feet is 3 bar.  give or take.

Damn, you said it easier than me. , from "diver thumb rules" above,

Every 33 feet is 1/3rd of a bar in saltwater
Every 34 feet is 1/3rd of a bar in freshwater