The Challenge: As a diver descends underwater, water pressure forces extra nitrogen into the diver’s body tissues. Divers must decompress (safely expel the nitrogen) when they return to the surface. Inadequate decompression can cause decompression sickness, a dangerous condition where gas bubbles form in body tissues.
The Solution: NEDU’s medical personnel began studying decompression sickness in the 1930s. They created procedures that helped divers decompress more correctly and developed methods for treating decompression sickness.
Decompression tables, first introduced in 1908, tell divers how to safely decompress after a dive. Divers use different tables depending on the dive’s depth and duration, the type of breathing mixture used, and the availability of a decompression chamber.
Beginning in the 1930s, NEDU developed key improvements to existing decompression tables when diving on air. Over time, NEDU developed additional refinements and new types of decompression tables for different breathing mediums and different diving equipment. Many have become the standard tables used worldwide.
Treating Decompression Sickness
NEDU personnel also devised treatment procedures for divers suffering from decompression sickness or gas embolism (bubbles in the bloodstream). Early treatment relied on re-pressurizing affected divers to deep depths while breathing compressed air. Improved treatment tables, introduced in the 1960s, yielded more effective results by administering oxygen therapeutically at shallower depths.