Captain Chris Murray, Supervisor of Diving at Naval Sea Systems Command in Norfolk, VA, takes his MK-21 Dive Helmet off after completing the in-water phase of his dive. Murray now has five minutes to get undressed and enter the recompression chamber where the air pressure around him will be brought to a depth of 50 feet; this is done to avoid decompression sickness. He will spend an hour and forty-five minutes in the recompression chamber to allow his body to off gas. Image courtesy of Monitor 2001, Monitor collection, NOAA/OER.