All Global Positioning System (GPS)-equipped 406 MHz emergency beacons are not created equal. In a recent test of six beacons from three manufacturers, the GPS location function of one manufacturer's products routinely failed when tested under other than ideal conditions. An equally important test finding was that the international standards to certify the GPS-enabled 406 MHz beacons fail to take into account the real-world conditions that often exist when beacons are activated.

The test was conducted by the Equipped to Survive Foundation, an independent reviewer of survival equipment, and funded by BoatU.S. Foundation for Boating Safety and Clean Water and West Marine. The beacons were specifically tested for their GPS functionality, or their ability to "self-report" their location to Geostationary (GEO) satellites, which can relay the location information nearly instantaneously to rescuers.

All of the six tested beacons primarily use the 406 MHz distress alerting frequency in conjunction with the COSPAS-SARSAT system of Low Earth Orbit (LEO) satellites and Doppler principles to provide position information. The report did find that all of the tested beacons successfully allowed a Doppler location to be derived - a minimal acceptable level of distress alerting. However, the purpose of GPS-enhanced 406 MHz beacons is to save precious rescue time by supplying much more precise location information via their own GPS-derived location through GEO satellites - ever present in the sky - rather than waiting for an orbiting satellite to appear in view and then obtain a less accurate Doppler computed location.

Equipped to Survive Founder Doug Ritter said, "Unfortunately, in the testing, the off-the-shelf McMurdo Ltd. 'Precision 406 MHz GPS EPIRB' (also known as G4 406 MHz GSP EPIRB) and the McMurdo Ltd. 'Fastfind Plus 406 MHz Personal Location Beacon' (also known as the Fastfind Plus 406 MHz PLB) both failed to reliably acquire a GPS location 'fix' under operational 'real-world conditions.' The tests revealed that purchasers of these GPS-equipped 406 MHz beacons - who paid a premium for the added GPS technology in the hopes of potentially shortening rescue response with faster location information and increased location precision - are apparently not getting what they paid for and are operating under false expectations. This lack of GPS data could result in tragedy that might have otherwise been prevented," continued Ritter.

The evaluation was divided into three distinct phases: Baseline, Maritime and Inland. Within each of the latter two phases, a series of tests was designed to replicate real-world conditions, with variables such as sea state, limited horizon, forest canopy, mountains and the number of GPS satellites in view.

BoatU.S. Foundation President Ruth Wood said, "Emergency beacons are often called upon to send an alert during inclement weather or less-than-perfect conditions. We tested the six beacons aboard a life raft, floated them in the water tethered to an inflatable or held by a swimmer in moderate one-to-eight-foot swells, the study showed clearly that the not all these beacons operated equally," she said. Inland performance was mixed, with McMurdo's PLB failing to acquire a GPS fix where handheld GPS receivers had no difficulty acquiring a location.

Additionally, the study identified other factors that could impact a 406 MHz beacon's GPS performance, as well as some generic 406 MHz beacon flaws worthy of note. Beacons that rely on an external GPS source are entirely dependent on the performance of that external GPS source - and the quality of GPS receivers varies significantly; submerging the base of some PLBs' antenna in water can adversely affect their ability to successfully transmit an alert under some conditions or to provide an effective 121.5 MHz homing signal.

"If there is a man overboard situation," said Ritter, "It's not a stretch to assume that their Personal Locator Beacon could also be partially submerged and rescue potentially compromised." The Equipped to Survive Foundation issued 17 specific Conclusions and 23 critical Recommendations for action based on the test results. "The bottom line is that while the international COSPAS-SARSAT system does an extraordinary job of saving lives, the COSPAS-SARSAT testing standard for GPS performance needs to better reflect real-world conditions. Consumer expectations regarding performance of these emergency beacons are very high - this is one area where those expectations must be better met," he concluded.

In response to the test results, West Marine announced that it will provide a full refund or exchange of the affected McMurdo products while it works with McMurdo to resolve the issues noted in the Foundation report.

The BoatU.S Foundation for Boating Safety and Clean Water is a national 501(c)(3) non-profit education and research organization funded by the voluntary contributions of 550,000 members of BoatU.S., the nation's largest recreational boat owners association. The mission of the Foundation is to promote safe and environmentally sensitive boating, reduce accidents and fatalities, and increase stewardship of our water resources. The Foundation operates the only accredited, free, online boating safety course, a low-cost EPIRB rental program, a free Kids Life Jacket Loaner program, and awards grants to non-profit groups for boating safety and environmental projects.

West Marine is the largest marine retailer and distributor in the world operating over 350 retail marine stores under the West Marine and BoatU.S. brands. In the pursuit of improving boating safety, West Marine has conducted numerous tests of marine equipment including anchors, life jackets, bilge pumps, life rafts, and pyrotechnic signals, and has co-sponsored other tests with well-known safety organizations. It is also a sponsor of the US Sailing Safety at Sea Seminar series, which educates offshore boaters in critical safety skills and equipment.