Doug Ritters’s http://www.equipped.org>Equipped performed tests on the new GPLBs with surprising and sometimes disappointing results. The results my be found [here
I recommend anyone that has such a device or is interested in purchasing them read the report. It contains interesting information about the devices limitations and shortcomings.
For a very brief summary, it appears that the devices are still a considerable improvement over the older ELTs, but the users should be advised to do their best to keep the units oriented vertically, keep the antennae free from water and try to ensure that the units have a clear view of the constellation of satellites. In general, a lot of us (I know that I do) believe that if something is new and uses more advanced or at least modern technology that it will do what it is advertised to do and have very high levels of reliability. In the case of GPLBs, while still a marked improvement on the ELTs, apparently they are not perfect.
For those of you who are unfamiliar with Doug Ritter and the “Equipped to Survive” organization, Doug was a guest speaker at last year’s Minnesota Migration. He gave a lecture on ditching the Cirrus aircraft and a separate, in-pool, participatory demonstration of life vests and life rafts. His presentations are always quite interesting and sometimes a bit controversial. I recommend that if you have any interest in survival techniques and equipment, you take a few minutes and review some of the materials that he has on his web site.](http://www.equipped.org/406_beacon_test_summary.htm#Summary)