The Importance of Understanding How the Underlying Principles of Decompression Theory Apply Differently to Dive Computers Than to Dive Tables
Matthew R Taitt · OpenSIUC (Southern Illinois University Carbondale) · 2003
Taitt 1• Even to those unfamiliar with the intricacies ofdiving terminology, "the bends" is probably a commonly known phrase.However, most outside the diving community do not fully realize the complexity of the ailment clinically known as Decompression Sickness (DCS) or Decompression Illness (DCI).It results from the nitrogen absorbed by the body under pressure being released too quickly as the ambient pressure around the body decreases.Unfortunately, itis not yet precisely known how much nitrogen the body can absorb or how quickly it can release the gas.H.V. Hempleman describes Decompression Sickness as a "man-made (disorder) for which the causative agent is easily established but the mechanism whereby the body reacts is not sufficiently understood."IThose in the diving world work on time-tested theories that have resulted in approximate limits on depth and time spent on a self-contained underwater breathing apparatus (scuba).For the typical recreational diver, these limits are imposed by one of two• sources: a dive table or a dive computer.Divers use these devices to formulate a dive schedule, the planned maximum depth and the time of any given dive.Divers need to understand how the underlying principles of Decompression Theory apply differently to dive computers than to dive tables in order to curb the risk of DCS. Diving ScienceContrary to Hollywood's erroneous images of secret agents jetting through the water on rocket-propelled fms, scuba divers are bound by the laws of science.Along with teaching students about diving equipment and skills, an introductory scuba course provides new divers with a rudimentary knowledge of physics.Obviously, people are surrounded by air at all times on land, but it is not so obvious that the air places weight on the human body along with all other things on earth.At sea level, a column ofair measuring 1 inch by 1 inch reaching the limit ofthe • planet's atmosphere weighs approximately 14.7 pounds.Therefore, this colunm exerts 14.7