The advantages of a 406 EPIRB are worldwide coverage, position location accuracy, a reliable transmitted signal, an encoded message that identifies the distressed vessel, and a faster response time.
The frequency stability of a 406 MHz EPIRB, which directly affects position accuracy, is about 10 times greater than the older homing-type 121.5 MHz EPIRB. Satellites can detect the 121.5 signal, but the location information they transmit is not as accurate, and there is no encoding information to identify your vessel. The location of a transmitting 406 beacon can be determined within approximately three miles by the first satellite pass, and to within one mile after three satellite passes. For a homing EPIRB, position accuracy is only 12 miles. It’s the difference between a 452 sq. mile search area versus a little more than three square miles. Also, the 121.5 frequency will soon no longer be monitored by our government Search and Rescue (SAR) for long range Search and Rescue. If this is what you’re using, it’s time right now to get a new 406 EPIRB.
406 EPIRBs also have a much greater power output. And noise interference is less, so the 406 can be more reliably detected over greater distances than most homing 121.5 EPIRBs. Once registered, the unique, encoded digital message received by the satellite and transmitted back to ground-based search and rescue authorities provides them with information to assist in the search-who you are, your boat type and size, where you are (within three miles), and other important data, including emergency contact information. The encoded signal also performs the important function of circumventing false alarms, which are the vast majority of transmissions from 121.5 EPIRBs.
If you would like to rent instead of buy a 406 EPIRB for your next offshore trip, visit the BoatUS Foundation for rental information.
It is critically important to register your EPIRB. It is quick and easy and this will help the Coast Guard establish quickly that your call is legitimate and it will help them to know what to look for, as well as giving the your contact info and emergency contact info. You can do this online.
If you want the best protection, (and you and your friends and family deserve it) consider one of the new 406 MHz EPIRBs which use GPS interface to communicate your position immediately, instead of waiting for satellite passes to pinpoint your location.
EPIRBS come in several types including those that float, personal locator beacons that can be worn on life jackets, those that automatically activate when wet and those that are manually activated. Some also have hydrostatic releases. Whatever you choose, familiarize yourself thoroughly with operating instructions so that you’ll instinctively know what to do if the time comes. It’s best to read operating instructions before you buy so that you have an even better idea of what’s best for you.
All commercial fishing vessels that operate beyond the three nautical mile line must be equipped with a 406 MHz EPIRB. Vessels less than 36′ may use a Category II 406 MHz EPIRB, which means it does not have hydrostatic release and must be manually launched. Vessels over 36′ must have a Category I 406 MHz EPIRB equipped with a hydrostatic release. Vessels over 36′ that have inherent buoyancy (foam, sealed chambers, etc.) to float when flooded may use a Category II 406 MHz EPIRB. These rules are subject to change, as is the equipment; keep up.