Abstract
Lost, disoriented, or entangled scuba divers are at risk of asphyxiation due to low air supply: time-sensitive situations that depend on timely “buddy rescue.” Similarly, avalanche victims die most frequently from asphyxiation if not rescued by a nearby buddy, with survival probability decreasing quickly, from 91% at 18 minutes after burial to 34% at 35 minutes. In these situations where elapsed time until rescue is one of the most critical variables of survival, using an avalanche beacon has resulted in a lower median duration of burial (5 minutes vs 125 minutes; P <.001) and rate of mortality (55.2% vs 70.6%; P <.001, odds ratio 0.26) when compared to avalanche victims not using a beacon. This knowledge and technology have made avalanche beacons part of standard backcountry travel gear and are now helping firefighters locate lost comrades and build exits when visual communication is impaired.
Scuba divers in low visibility situations may also benefit from a personal, hand-held device that helps locate their buddy if visual communication is lost. Modern day avalanche beacons may serve this purpose.
Initial testing was carried out in the shallow end (3-foot depth) of a local 100-foot by 50-foot swimming pool. Four submerged, identical, opaque, watertight lexan cases were submerged to the bottom in the four corners of the pool's shallow end. One of the cases contained a Tracker DTS avalanche beacon in “transmit” mode. Volunteers used an identical avalanche beacon in “search” mode, and encased in a similar but clear, water-tight case, to identify which of the 4 cases contained the missing beacon. Ten out of 10 volunteers, each with minimal training and within 1 minute 30 seconds, were able to use the “tracking” beacon to locate the “missing” beacon. Avalanche beacon reception under water is possible and warrants further study applying its technology to underwater applications.