Potential Benefits of Navy Dive Computer Use in Ships Husbandry Diving: Analysis of Dives Conducted at Puget Sound Naval Shipyard

Abstract

Generation III Air Navy Dive Computers (AIR III) were used to record 315 ships husbandry dives conducted by divers breathing air at the Puget Sound Naval Shipyard from November 2007 to January 2008. For each profile, decompression status was assessed from the air tables in Rev. 6 of the U.S. Navy Diving Manual and from the AIR Ills, thirty-five dives were repetitive dives (within 12 hours of a previous exposure), so 280 are distinct profiles for analysis. According to probabilistic models, the average predicted risk of decompression sickness for these profiles was low (<1 %), as expected. The majority of dives ended because the assigned work was completed, not because the no-stop limits for the maximum depth were reached. Two 34 fsw profiles were of moderate risk when evaluated by both USN93 and BVM-3 These two profiles exceeded the Rev. 6 U.S. Navy Diving Manual no-stop limits, and one of them required five minutes of decompression per the AIR III record. More than 10% of the dives were conducted at or beyond the no-stop limits for Rev. 6 of the Diving Manual; divers would have directly benefited from using AIR Ills on these dives. The AIR Ills will also benefit these divers in cases where a diver needs to make a downward excursion (tool recovery, etc.), but until divers are allowed to dive per the guidance of the AIR Ills, we will be unable to fully tabulate the benefits. A future AIR III benefit for divers will be a reduction in data entry when the Navy Dive computer profiles are downloaded into the Dive Recording System, an expected by-product from development of the Topside Decompression Monitor.