Tests conducted in varying conditions
The McMurdo beacons were among six EPIRBs and PLBs that the Equipped To Survive Foundation tested last January in California, both landside and on Monterey Bay. Other models were ACR Electronics’ RapidFire 406 MHz EPIRB that connects to an external GPS, GlobalFix 406 MHz EPIRB with integral GPS, and GyPSI 406 MHz PLB with external GPS, and Techtest Ltd.’s Model 500-27 406 MHz GPSPLB with integral GPS.
The tests were performed on a jetty and a beach with a clear horizon; on a boat’s aft deck under the mizzen mast in 8-foot swells; in the water with the unit tethered to a rigid-hull inflatable in 8-foot swells; with the unit held by a swimmer tethered to a RIB in 2- to 3-foot seas; with the unit secured to a life jacket on a simulated swimmer in 2- to 3-foot seas in simulated rain; in the water, the unit floating free in glassy conditions; and in a six-person life raft with canopy open and closed in 2- to 3-foot swells, in clear weather and simulated rain. A beacon was deemed to have failed if it hadn’t acquired a GPS fix in 35 minutes.
ETS executive director Doug Ritter says his test results showed the ACR and Techtest beacons with integral GPS can be expected to acquire a GPS fix under most moderate sea and weather conditions.
“The ACR GlobalFix 406 EPIRB and Techtest Model 500-27 PLB generally provided location information within a few minutes from activation under all but the most onerous scenarios tested, with a few exceptions,” Ritter reports in a summary of his test results (available at www.equipped.org).
“By contrast, the McMurdo Fastfind 406 PLB and McMurdo Precision 406 GPS EPIRB generally failed to provide location information except under ideal conditions,” the report says. “Even in scenarios where there were strong signals from four or more GPS satellites, and often six or more … these beacons failed to provide a location unless the sky view was virtually unimpeded over the full hemisphere, and there was little or no movement of the beacon due to the motion of the water.”