The test summary
The tests conducted by the Equipped To Survive Foundation revealed these specific findings:
• The McMurdo beacons often don’t acquire a GPS fix “unless environmental conditions are generally benign and the beacon is stable, and unless there is a largely uninterrupted sky view covering most of 180 degrees above and 360 degrees around the beacon location.”
• Boaters accustomed to using a moderately priced Garmin eTrex GPS receiver to navigate can expect ACR beacons to perform comparably to that unit. They can expect Techtest beacons to perform comparably in all but the most challenging conditions. McMurdo beacons are likely to fail in conditions where the Garmin eTrex GPS typically fixes a location.
• None of the beacons tested — whether they have integral GPS or are connected to a Garmin eTrex external GPS — are likely to perform as well as a higher performance GPS receiver, such as a Garmin GPS 12 or GPS V.
• Where an external GPS was used with a beacon, the performance of the beacon entirely depended on the quality of the GPS unit. The Garmin eTrex Legend GPS was chosen as the standard external GPS for the trials. In cases where this unit failed to acquire a location, a better quality and more expensive GPS would have been able to acquire one.
• The 121.5 MHz homing signal on PLBs with blade antennas is significantly degraded when the antenna base is submerged in water.
• When a PLB’s antenna base is submerged, the 406 MHz signal is significantly weakened, as well. Only the Techtest PLB with its conventional 50-ohm telescoping antenna successfully transmitted a distress signal to the geostationary satellite under these circumstances. There was no expectation of acquiring a GPS location because the GPS antenna was submerged.