CASANOVA MARINE

COMMERCIAL DIVE SUPPLY WORLDWIDE

What Does It Mean?

Glossary of Terms

The total pressure, including atmospheric pressure.

The absolute pressure at a specific location.

The pressure at a location, including the pressure of the atmosphere; also the term "Ambient Pressure" is used. Note: Pressure gauges typically do not display "absolute" pressure.

 The pressure at the surface of the earth is simply referred to as 1 atmosphere absolute (ATA).   For each 33 fsw (34ffw) of water, an additional atmosphere is added.  Since water is not compressible, ata can be used as a depth-in-water reference standard of measure.  Depth Gauge Review & Diver's Dive Table Skill Set Review

"Boyle's Law" is a description of the properties of gas-volume and gas-pressure relate.

A group of dive tables formulated by Dr. A. Buhlman, a prolific hyperbaric physiological researcher.  There are many different tables, but a select few are common in the sport diving world.  Some dive computers are based on the 'Buhlman Tables'.

Central Nervous System.  Used with other terms like CNS Oxygen Toxicity; meaning the effects of oxygen toxicity on the central nervous system.  When used in diving, relates to the brain, brain stem and in some cases the spinal cord.

Central Nervous System oxygen toxicity characterized by a Short Term High Dose of oxygen (greater than 1.0 ATA).  Sometimes referred to as the "Paul Bert effect".  Diving exposures up to an oxygen pressure of 1.6 ATA are time defined by the NOAA guidelines.  May result in seizures if the guidelines are ignored.

Plan Your Dive, Dive Your Plan!

Feet of Fresh Water. A imperial unit of water depth measure.

Feet of Sea Water. A imperial unit of water depth measure.

Chemical symbol for Mercury.

Hydrographic charts are maps that represent the surface and shores of large bodies of water on earth. Ships navigate by using hydrographic charts.

Standard for "Inch of Mercury"

National Oceanic and Atmospheric Administration

Pressure of a gas

Pressure of nitrogen, the nitrogen symbol may be replaced by any other gas symbol depending on use.

Pressure Total (Total Pressure).  The pressure at a specific location that includes the effect of the atmosphere.

Residual Nitrogen Time

Surface Interval Time