Marine Science Affairs 



— initial use of the prototype Navy Mark I and Mark II Deep Dive 



System, designed for 1000 feet; 

 — fabrication of an experimental model communication system that 

 has shown superior intelligibility to the 600 feet depth with the micro- 

 phone and electronics contained in the facemask; and 

 — completion of studies suggesting that (a) in the United States satu- 

 rated diving may account for 50 percent of all military diving in 

 1980, (b) divers will have adequate natural visual perception only 

 5 percent of the time, (c) self-contained communication equipment 

 capable of 90 percent intelligibility within a range of 2,000 yards at 

 a depth of 1,500 feet is capable of meeting most diver portable 

 communications requirements, and (d) compact underwater heaters 

 are required to protect divers from environmental cooling. 

 The Navy is constructing a nuclear powered research and ocean engi- 

 neering submersible (NR-1 ) which combines the long endurance of a nuclear 

 power plant with the control and instrumentation developed for the DSRV 

 rescue submersible. Carrying a crew of five plus two observers, the NR-1 will 

 also provide the technical basis for future development of nuclear-powered, 

 oceanographic research and survey submersibles to operate at even greater 

 range and depth. Current scheduling calls for sea trials and operations in 

 early 1969. 



Biomedical Researcli and Development 



Advanced biomedical activities of the Navy Bureau of Medicine and 

 Surgery are developing criteria for life support, health maintenance, 

 and environmental control at 1,000 feet underwater equivalent pressure. 

 A joint Navy-Duke University saturation dive to a simulated depth of 

 1,000 feet was completed in December 1968. During the 77 hours and 30 

 minutes spent at saturation depth, the divers performed extensive physical 

 and medical tasks in a normal manner. All observations indicated that 

 divers can perform well under these conditions if life support systems main- 

 tain a level of support equivalent to that at the surface. The detailed medical 

 results of the dive, to be published in the near future, will make available 

 comprehensive information in such areas as heart rate, respiration frequency, 

 oxygen consumption, carbon dioxide elimination, partial pressure in arterial 

 blood of oxygen and carbon dioxide, central nervous system function under 

 various conditions, and human performance and reaction response at deep 

 depth. 



Priority in FY 1970 will be given to (a) calculation and evaluation of 

 several sets of decompression schedules for use in four diflferent fleet systems, 



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