The following are the constants used for the PADI Dive Theory Exam:
Metric
Metric
- 1 litre of salt water weighs 1.03 kilograms
- 1 litre of fresh water weighs 1 kilogram
- Pressure increases by 1 ATM every 10 metres of salt water
- Pressure increases by 1 ATM every 10.3 metres of fresh water
- Pressure changes per unit of salt water = 0.100 ATM/m
- Pressure changes per unit of fresh water = 0.097 ATM/m
- 1 cubic foot of salt water weighs 64 pounds
- 1 cubic foot of fresh water weighs 62.4 pounds
- Pressure increases by 1 ATM every 33 feet of salt water
- Pressure increases by 1 ATM every 34 feet of fresh water
- Pressure changes per unit of salt water = 0.445 psi/ft or 0.0303 ATM/ft
- Pressure changes per unit of fresh water = 0.432 psi/ft or 0.0294 ATM/ft