Scope and design of the GUSI international research program

During the 1980s a large new simulated underwater saturation diving system was constructed at GKSS, Geesthacht, Germany. This German Underwater Simulator (GUSI) has performed over 18 trimix (helium, 5% nitrogen, oxygen) dives with 115 divers at depths to 600 m, including 9 to 450 m or deeper for a total of 2672 man-days of saturation and 994 days of welding and other work. From October 1989, an international research program was initiated to permit scientists from other countries to carry out physiologic and medical research during these working dives. The results of the first year's program from 3 dives, GUSI 14, 16, and 17, all to 450 m, are described in this special edition of Undersea Biomedical Research. This brief paper gives the scope, design, and objectives of the program, the dive profiles, and the scientists and projects involved.