- Water is 800 times denser than air.
- Sound travels about 4 times faster in water (just under 1 mile/sec).
- Water absorbs heat 20 times faster than air.
- A cubic foot of sea water weighs 64lbs.
- A cubic foot of fresh water weighs 62.4lbs.
- Every 33 feet of sea water = 1 ata or 14.7psi.
- Every 34 feet of fresh water = 1 ata or 14.7psi.
- The pressure in a scuba tank is raised to 166% (5/3) of it`s working pressure during a hydrostatic test.