The PLB is much more reliable and redundant, and the signal directly reaches official rescue authorities much quicker- but it is a rescue beacon only, with no '

The PLB is much more reliable and redundant, and the signal directly reaches official rescue authorities much quicker- but it is a rescue beacon only, with no 'tracking' or messaging abilities. A communicator can send your location and status- and newer more expensive ones can even do two way texting, and can call for help, but it is not as much of a serious emergency rescue device. In the USA boats over 55 feet are required by law to carry a PLB or EPIRB (e.g. a large PLB that is attached to the boat rather than a person) that is registered with NOAA with the vessel details. I'm a 'belt and suspenders' type person and on very remote wilderness or sailing trips I carry a PLB, a SPOT tracker (a communicator brand), and an iPhone in a rugged waterproof case with a waterproof wireless backup battery and solar charger.