that has revealed certain deficiencies in DSRV performance that are 

 being corrected. For example, at the present time, batteries do not 

 provide sufficient reliable sustained power. Therefore, the 

 engineering program is undertaking the development of a fuel cell 

 suitable for deep ocean applications. This effort was initiated in FY 

 '74 and is expected to continue through FY '79. 



In luly 1972 a recordbreaking open sea dive was conducted by U.S. 

 Navy divers to a depth of 1,010 feet. The dive was conducted in 

 conjunction with the operational evaluation of the Deep Dive 

 System, Mark 2 — Mod O. This dive was a test of selected, newly 

 developed equipment and techniques. In other efforts to improve the 

 safety and efficiency of diver operations, the Navy is continuing its 

 work on diver heating apparatus, communications gear, 

 physiological monitoring equipment, means of conserving or reusing 

 breathing gases, diver navigation equipment, and diver tools. 

 Physiological monitoring equipment is presently undergoing testing 

 and evaluation. 



The Navy's deep submergence biomedical research program 

 constitutes about 90 percent of the nation's research in this field. The 

 objectives of the program include determining man's physiological 

 diving limits while providing the biomedical knowledge necessary 

 for safe support of deep submergence operations. Decompression 

 schedules for various deep dive systems have been developed, 

 tested, and refined. Thermal requirements of divers in various 

 environments have been defined to provide data necessary for the 

 development of diver heating systems. Studies have been initiated 

 with animals to identify drugs that will prevent decompression 

 sickness and oxygen toxicity. Methods are being evaluated to 

 prevent and treat hearing loss in divers. Future work will also 

 include evaluating the doppler bubble detector as a means of 

 determining the onset of decompression sickness. 



The salvage program is designing and testing equipment to permit 

 the recovery of large objects from 850-foot depths. Shallow water 

 tests, to 100 feet, have been conducted with pontoons providing 100 

 tons of lift. Pontoon dewatering techniques that have been tested 

 include the use of compressed air and liquid nitrogen. A pontoon 

 propulsion system has also been fabricated and undergone 

 preliminary tests. Two pontoons will be fabricated with propulsion 

 and dewatering subsystems. A final test of this system, involving 

 salvage of a large object, is planned for FY '76. Studies on breakout 

 forces have been conducted, and an explosive system capable of 

 penetrating heavy steel plates to provide lift points has been 

 successfully tested. 



There is also a small program directed towards improving 

 oceanographic survey instruments. Most instruments are available 



88 



