John R. Clarke, Ph.D., has been the Scientific Director of the Navy Experimental Diving Unit (NEDU) since 1991. From 1979 to 1991 he conducted diving research at the Naval Medical Research Institute (NMRI), Bethesda, MD where he was the Program Director; Diving Life Support Equipment. He was an NIH Fellow in Respiratory Mechanics at the University of Florida School of Medicine from 1977-1979, where he conducted human research on a deep saturation dive to 1500 fsw at NEDU. While at NMRI he conducted human research during a 1990 trimix dive to 450 msw in the GUSI deep diving complex in Geesthacht, Germany. He received his Ph.D. in physiology from FSU, M.S. and B.S. from Georgia Tech. He serves on the Diving Control Board for Florida State University (recently resigning as Chair of the Board), and is on the National Science Foundation Antarctic Science Diving Control Board. He is a Fellow in Undersea and Hyperbaric Medicine, and enjoys flying, diving, and writing novels about military diving.