This course examines the use of EAN 21 through 100% (oxygen) for optimal mixes to a depth of 130fsw/40msw. The object of this course is to train divers in the benefits, hazards and proper procedures for utilizing EAN 21 through 100% (oxygen) for dives not requiring staged decompression. (Decompression techniques may be combined with this course at the discretion of the instructor).