Various types of decompression tables are available for divers. These decompression tables include the Air Table, and Hempleman’s. Both tables have their own benefits and drawbacks. These tables need to be used with care. A diving guide should always accompany the decompression table.
Air Table decompression tables
Decompression tables have been developed since the 1930s, when the Navy's Naval Experimental Diving Unit first created standardized tables that were based on a theory. According to this theory, the human body can eliminate nitrogen in a linear manner rather than at an exponential pace. To accommodate this theory, decompression tables have been created to help divers stay safe and sound underwater.
Divers used to use 'per container' accounting in the beginning. This is a more conservative way of determining nitrogen content. This method uses the M-values matrix to compare the various compartment gases. These values are commonly referred to by divers as "half-times", but it is important to remember that they are mathematical expressions and not real entities. This method is conservative in the short-term and may not be correct for deep, long dives.
Hempleman's Decompression Tables
Val Hempleman's decompression tables helped the Royal Navy stay on the cutting edge of deep diving technology and saved many lives. Hempleman was the Royal Naval Physiological Laboratory's superintendent between 1968 and 1982. He worked tirelessly to "overcome the bends." His research on the decompression tables was instrumental in helping a man survive for ten consecutive hours at a depth of 1.535 feet.
Hempleman modified his tables and added a variable proportion of tissue nitrogen tension to ambient. This was done in 1968. He was initially unable to get the Navy to adopt the new tables, but made modifications based on his practical diving experience. In 1972, the Navy adopted the updated tables.
Hempleman's revised tables of decompression
Hempleman revised the decompression tables for diving in 1968. These tables provide a variable ratio in tissue nitrogen tension to ambientpressure. Although the Navy initially did not like these results, Hempleman modified the tables for practical purposes and the new tables were eventually adopted by the Navy in 1972.
In 1908, Haldane's first table model was published. In 1908, Haldane published the first known diving tables. He was an adventurous self-experimenter. His experiments also included animal studies and the design of the British Admiralty's first decompression tables. As a clinical endpoint to decompression sickness, Haldane's suggestions were extensively used.
Hempleman's modified despression tables
Hempleman revised decompression charts in 1968 to incorporate a variable ratio for tissue nitrogen tension and ambient press. However, the Navy refused to approve the changes and refused the tables' implementation. Hempleman was able to modify the tables for practical reasons. Later, these tables were reprinted in metric units and adopted by the U.S. Navy on February 2, 1972.
The British Royal Navy adopted them in 1908, and they continued to use them until the 1950s. The U.S. Navy also began using the C and R tables in the same decade. This practice was popularized in the 1980s.