Manned Evaluation of a Prototype Cold Water Diving Garment Using Superinsulation Aerogel Materials

During January 2005, the U. S. Navy Experimental Diving Unit (NEDU) in Panama City, Florida conducted a repeated measures series of twelve test dives, each up to three hours in duration, to compare the thermal performance of a prototype diving garment using a superinsulation aerogel fabric with that of a commercially-available Thinsulate garment worn beneath a commercial dry suit. The thermal benefit of the experimental aerogel garment was determined by statistics describing psychological and physical thermal status data from the aerogel and the commercial Thinsulate garments. All tests were conducted to simulate long-duration cold water conditions in the NEDU test pool, where water temperature was maintained between 1.7 and 4.4 °C (35 and 40 °F). Divers remained immobile while either lying or sitting in chairs on the bottom of the test pool, and they subjectively reported their thermal comfort at 30-minute intervals during each dive. Mean dive durations were found to be approximately 43% longer when divers wore the prototype aerogel garment than when they wore an M400 Thinsulate liner. The prototype aerogel garment also enhanced thermal protection to the fingers and toes, although thermal stress to these body regions still remained the most frequent reason for aborting dives. Future research should include work on localized active heating of the hands and feet to augment the thermal insulation of the prototype aerogel garment.