Consequently, US Navy Diving tables are being followed globally by a variety divers ranging from recreational to scientific to Technical divers. In order to ...
Comparison of Decompression Practices of Indian and US Navies Lt Cdr Mohammed Ikram Submarine Rescue Officer INS Nireekshak Surg Lt Cdr Rohit Verma, MBBS, DMM Graded Specialist & PMO INS Nireekshak Abstract
Background: The US Navy has been a pioneer in experimental diving practices and has evolved one of the safest decompression protocols. Consequently, US Navy Diving tables are being followed globally by a variety divers ranging from recreational to scientific to Technical divers. In order to increase understanding and cooperation in subsea operations, Indian Naval divers participated in an exercise in which USN decompression practices were followed. Method: Two IN clearance divers along with Two USN salvage divers undertook a dive to 42 MSW on a stage through surface supplied compressed air gas for a bottom time of 22 minutes. Decompression Practices as per USN Diving Manual was followed. The divers underwent Surface Decompression with Oxygen (Sur D O2). Results: The dives were uneventful and did not result in any dive related morbidity or Non Dive Related (NDR) incident. The practice of Sur D O2 involved rapid controlled ascent and immediate transfer to a previously prepared chamber for Oxygen based decompression. The decompression was accelerated in comparison with the IN diving practices. A significant amount of time was saved in the diving operation with Sur D O2 in comparison with In water stops being followed by IN. Conclusion: The USN practice of Sur D O2 is based on extensive surface support and immediate transfer to a stand by chamber. It capitalises on the oxygen window concept to accelerate the total decompression time. Further, it replaces the uncontrolled environment of the ocean with the controlled environment of the chamber thus reducing the possibility of Hypothermia; Barotrauma; Cerebral Arterial Gas Embolism (CAGE); buoyancy related morbidity and Marine Animal injuries. However, it also slightly increases the risk of DCS in the immediate aftermath of ascent as well as is extremely resource intensive. Keywords: Diving Medicine; Decompression sickness
