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Author Topic:   EPIRB 121.5 MHz Monitoring By Satellite Ends
jimh posted 01-31-2009 10:01 AM ET (US)   Profile for jimh   Send Email to jimh  
[Added notation of "by satellite" to topic to clarify--jimh.]

As was announced by the International Cospas-Sarsat Council (in conjuction with IMO/ICAO) at its 25th General Session in October 2000, the monitoring of EPIRB distress signals by satellite on 121.5 MHz will end on February 1, 2009.

Mariners have had over eight years of prior notice of the termination of this service. Use of these devices has been prohibited in the U.S. for over two years. Recent United States Coast Guard NOTICE TO MARINERS have included an advisory about the pending termination.

The Coast Guard also recently published this FACT SHEET:


Termination of 121.5/243.0 MHz
Processing on Cospas Sarsat Satellites

"The International Cospas-Sarsat System will cease satellite processing of 121.5/243 MHz beacons on 1 February 2009. All beacon owners and users should begin taking steps to replace their 121.5/243 MHz beacons with 406 MHz beacons as soon as possible."
--International COSPAS SARSAT organization with guidance from the UN.

"Operation of Class A/B/S EPIRB stations shall be prohibited after December 31, 2006."
--47 CFR 80


The International COSPAS-SARSAT Program's mission is to protect life and property by providing accurate, timely, and reliable alert and location information from persons in distress to search and rescue authorities. Due to numerous signal reception problems, a high incidence of false alerts (over 97%), and a host of other limitations associated with the 121.5 and 243 MHz frequencies, the International COSPAS-SARSAT Program, with guidance from the United Nations, decided to terminate the processing of 121.5/243 MHz alerts by the COSPAS-SARSAT satellite system as of 1 February 2009.

Talking points

Class A, B, and S (121.5/243 MHz) Emergency Position Indicating Radio Beacons (EPIRBs) were prohibited from use in all watercraft effective 1 January 2007

Refer to 47 CFR Parts 80.1051 through 80.1059.

These FCC regulations apply to EPIRBs that transmit a distress signal to satellites on the 121.5/243 MHz frequencies. There are a few FCC exceptions to these regulations including the popular ACR Mini B "personal EPIRB" which is only authorized for use as a local man overboard device. Also, other low powered 121.5 MHz Man Overboard Devices that do not transmit to the satellites are still legal for use.

These regulations are part of a phased plan to remove all distress alerting beacons operating on the 121.5 and 243 MHz frequencies prior to 1 February 2009 when satellites will no longer process these frequencies.

Coast Guard personnel (Boarding Officers, Inspectors, Auxiliary, etc.) and EPIRB owners must check the class or type of beacons carefully since both the prohibited 121.5 MHz EPIRBs and the authorized 406 MHz EPIRBs contain a 121.5 MHz homing signal which is used for direction finding purposes.
If a 121.5/243 MHz EPIRB is used in a distress situation after 1 January 2007, Coast Guard units will still respond, recognizing that mariners should use any available means to signal distress.

Boaters who activate their EPIRB in a non-distress situation such as a false alert, whether intentional or not, may be subject to FCC penalties for operating a "prohibited device."

Current US law associated with this regulation has prohibited the sale of 121.5 MHz EPIRBs, since 1 February 2003.

The 406 MHz EPIRB has proven to be a more reliable beacon with reduction in false alerts and a significant increase in positional accuracy and quicker alert notification.

The 406 MHz signal is approximately 200 times stronger than the 121.5 MHz "homer" on 406 MHz EPIRBs; as such, CG aviation response assets, at altitude, can easily lock onto this stronger signal from 100+ NM away (S/V Paradox, F/V Silver Wings). Additionally, because of its strength, the 406 MHz signal easily penetrates ship hulls, buildings, even the human body whereas the 121.5 MHz signal is easily attenuated.

Boaters who have not already done so should consider purchasing a 406 MHz EPIRB (or a 406 MHz Personal Locator Beacon (PLB) if EPIRB carriage is not mandatory) given the new regulation prohibiting 121.5 MHz EPIRBs and the numerous advantages of a 406 MHz beacon. Pilots are also encouraged to purchase 406 MHz ELTs for their aircraft before the 1 February 2009 date when satellite detection of all 121.5 MHz beacons terminates.

When taking obsolete beacons out of service, owners must remove and properly dispose of batteries to prevent future false alerts from occurring.

Beacon owners in the United States are required by law to register their 406 MHz beacons with NOAA at

or by calling 1-888-212-SAVE. Registration information includes the owner's contact information, emergency contact information and characteristics of their boat or aircraft. Registration is easy, free, and can only be viewed by authorized Search and Rescue authorities.

406 MHz beacon owners must update their registration information every two years or whenever it changes.

Issue date: 3 Mar 08
USCG SARSAT Officer: LCDR Kathy Niles

David Pendleton posted 01-31-2009 03:10 PM ET (US)     Profile for David Pendleton  Send Email to David Pendleton     
Bummer for everyone who spent several grand on a Breitling Emergency...
jimh posted 01-31-2009 08:16 PM ET (US)     Profile for jimh  Send Email to jimh     
Sale of 121.5-MHz devices has been prohibited for six years. If someone bought one, they bought it a while ago.
Tohsgib posted 02-02-2009 01:09 PM ET (US)     Profile for Tohsgib  Send Email to Tohsgib     
When they were phasing them out in 2002 I know a bunch of people who bought them for like $150(compared to $700+ for a 406). Better than nothing and it worked for 7 years or so.
David Pendleton posted 02-02-2009 11:31 PM ET (US)     Profile for David Pendleton  Send Email to David Pendleton     
Not quite, Jim. Brietling (and most likely others) continue to sell 121.5 devices:

jimh posted 02-02-2009 11:45 PM ET (US)     Profile for jimh  Send Email to jimh     
You're talking about a wrist watch, not an EPIRB device.
jimh posted 02-03-2009 12:16 AM ET (US)     Profile for jimh  Send Email to jimh     
What has happened just recently is that the satellite monitoring of 121.5-MHz for signals from an emergency position indicating radio beacon (EPIRB) has ceased. According to COSPAS-SARSAT:

'However, other devices (such as man overboard systems and homing transmitters) that operate at 121.5 MHz and do not rely on satellite detection will not be affected by the phase-out of satellite processing at 121.5 MHz."

For further information

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