USGC switch to digital radio frequencies

I came across the following news item on the web. Do any of you hand held Marine Radio VHF gurus know if this switch impacts the Coast Guard’s monitoring of marine vhf distress calls?

“Associated Press —

SAN JUAN, Puerto Rico (AP) – The U.S. Coast Guard says it will no longer respond to distress calls sent by analog signal starting Feb. 1. The agency is switching to digital frequencies and says the new equipment cannot process signals transmitting on 121.5 or 243.0 MHz.

The Coast Guard said Wednesday in a statement that the switch to digital will provide a more stable and powerful signal that could improve response times.

The agency said mariners and aviators should upgrade their equipment to include a digital 406-MHz distress radio beacon and register it online.”

Here’s a link to the source:

for emergency beacons, not normal VHF

The 121.5 mHz distress beacons were just emergency radio signals (like a strobe, but instead of light it emitted a specific radio frequency which satellites would relay to land stations). Any transmission on that frequency was a distress call, and the transmissions didn’t contain any data (such as position or identity).

The 121.5 frequency is still used for MOB recovery beacons worn by deckhands (where the ship acts as the recovery platform for it’s own MOB), and other homing beacon type stuff, but the international rescue organizations (COSPAS-SARSAT) aren’t listening on that frequency anymore.

The 406 Epirbs have replaced the old analog system. These digital signals transmit ship’s information like identity, emergency number, etc., and position if connected to a GPS.

I don’t fly anymore but 121.5 was the frequency we were supposed to holler for help (may day) on. Sounds like no one will be listening anymore.

121.5 ELTs

It’ll still be a good idea to monitor 121.5 – could help a fellow plot.

121.5 mHz is the International Disress

– Last Updated: Jan-24-09 2:35 PM EST –

..... call frequencie for civil "aeronautical" transciever communications . It is reconized , monitored and used by all ATC , FSS , air traffic communication facilitys and pilots . Nothing has changed here with regard to voice transmission of distrees calls for aircraft .

An aircraft transponder can also be set to certain codes that have specific meanings allocated to them , for argument sake we can identify these codes as emergencie codes , they will get the attention of ATC immediately be acted upon .

406.0-406.1 is the newest ELT transmission frequencie monitored by the Satalites .

Voice communication Distreess calls for Maritime can still be made over 156.8 ... this is your VHF channel 16 , channel 9 is a secondary maritime distress frequencie .

Yes, the CG

– Last Updated: Jan-24-09 10:23 PM EST –

is no longer monitoring 121.5 analog ELTs. When you purchase a EPIRB, PPRIB or PLB make sure it's a 406. This switch has nothing to do with VHF.

As far as VHF, channel 16 is a hailing and distress frequency. Channel 70 is what DSC distress alerts are received on. Channel 9 is not a distress frequency. The CG does not have the capability to monitor VHF channel 9 so I would not suggest you rely on it for distress. Distress freqs the CG does monitor are CH16 and CH70.

With the new Rescue 21 system (that's the CG radio system) the frequencies are pre-set. Channel 9 is not one of those freqs. Matter of fact, neither is channel 13, which ticks me off, but my voice has fallen on the higher up's deaf ears.

You guys are talking Greek to me,
but I was talking to some search and rescue Coasties last weekend and they said they really need people to use up-to-date EPIRBS in emergency situations. They said using VHF channel 16 is unreliable, especially if you can’t give them your exact coordinates. I always had a great sense of security with my radio, but no longer. I don’t always take a GPS and don’t know if in an emergency that I could always exactly communicate where I was located. Even if I had a GPS, I don’t know if I could juggle that with a radio, paddle, boat, etc.

for an alternative, check out SPOT
locater beacons at They are similar to an EPIRB, but can also send “OK” messages to anyone you choose.

This system will send your GPS position automatically to their monitoring stations which in turn notify the CG, SAR, or the US Embassy if in a foreign country.

I thought about trying to help …

– Last Updated: Jan-25-09 3:08 PM EST –

..... explain some of this to anyone interested , but then thought it better to provide a link that will explain it all better than I could .

The net. is a great source for educational purposes these days ...

the least I would recommend is reading "How SARSAT Works For You" from the left column menu .

ed: ... just took a look myself at the link provided ... there is a "Frequently Asked Questions" in the left menu also ... it is very good info.

Using channel 16
This may depend a bit on where you paddle. In areas where there are strong commercial interests, like fishing fleets, everything I’ve seen is that channel 16 is still correct to use for a variety of emergencies like a paddler being stranded on an island etc. The emergency beacons, with GPS sent as part of the signal (I think most if not all the ewer ones do that), are obviously faster but may not be the only way to handle a situation where someone does need help but isn’t at risk of succumbing in the next hour.

As to saying where you are, we tend to forget in an age of technology that a fairly good location can be sent without a GPS fix. If you have a marine chart (and compass) and stay aware of where you are on that chart as you paddle, and know the tide and current behavior as well, you could tell the CG pretty well where you are from landmarks and your relative position as well as which way you are being carried (assuming out of the boat). It may not be as precise as a GPS fix, but for a lot of situations it’d do fine.

As to the announcement about the CG no longer responding to calls from beacons operating on the lower megahertz, I hope anyone who relies on that was alert to this when they announced the upcoming change a year ago. It’d be annoying to have spent good money on one of the older units not realizing that was why it was on such a good sale price.

remember that the SPOT is an unregulated commercial device, and that EPIRBs are part of a regulated global system. Each has advantages, but there are significant differences.

One skeptic’s view

in regards to EPIRB’s …

– Last Updated: Jan-25-09 2:41 PM EST –

...... (emergency position indicating radio beacon's) which are maritime units , primarily designed to be used on large and open bodies of water) ... since the FCC issued the order that 'class A,B,S Epirb's "Shall Not" be manufactured , imported or sold after "Feb. 1, 2003" , it would stand to reason that any "NEW" EPIRB purchased since that date will be a 406.0 capability unit .

Further , any pre-existing older (than Feb. 1, 03) 121.5/243.0 EPIRB unit cannot be used after the end of 2006 (FCC ruling)... using it is illegal if you still have one .

For inland hiking, canoing, camping, etc., the prescribed unit is a PLB (personel locating beacon) ... "all" of these units have always been a 406.0 MHz transmitting unit since authorized and produced for public use ... also , the USAF is the responsible coordinating SAR for inland rescues .

NASA is a big player here responsible for the incorperation of SAR (search and rescue) integrated into the GPS navigational satellite system , the MEO (medium earth orbit) navigational satellite system (otherwise known as your GPS)... the MEOSAR payload packages that have been and are being installed on all block-3 satellites (this is the navigation constallation of satellites orbiting the Earth /US NAVSTAR or GNSS) , and the program is called DASS (Distress Alerting Satellite System) .

The intergration of GPS reduces the search parameters from something like 1200 sq. kilometers to a football field size location ... a good thing .

Are you sure that using the 121.5 Mgh is actually illegal, like you could get a citation? I just did a quick check of EPIRBS (and what are called GPIRBS) for sale and found a few reputable-looking places selling a hand-held EPIRB at this frequency. Granted a whole lot fewer than a year ago, but a couple of models are still out there for sale. One place mentioned that you had to use a Vector something or other with it, the other one didn’t. In any case, there were no warnings about potential illegality.

I doubt that anyone who has been following this upcoming change would have one of the older units anyway. My comment on that was pointed towards those who were not aware of this upcoming change.

Celia , it took me a few minutes to …

– Last Updated: Jan-26-09 1:53 PM EST –

...... pull up something "credible" from the web. to substantiate my previous statement regarding the FCC ruling .

I have not stayed up to snuff about this subject , so there is always the posibility that certain waivers or contestents have the matter tied up somewhere beyond my knowledge , and if so I wouldn't mind hearing about them ... but this is from my recollection , the following FCC mandates concerning 121.5 MHz distress beacon usage in EPIRB's .

They are known as 47 CFR 80 , 1053 , 1055 , and 1059 .

specific: ...

soooooo , if someone is currently selling 121.5 MHz only EPIRB's , it has been my understanding that "it is illegal" according to Federal Law ... and has been since Feb. 1, 2003 .

406.0 MHz EPIRB's probably still have 121.5 MHz low range (low power) homing capabilty though , I would expect that though I am not certain of it ... overflying SAR aircraft would use it to home-in just as before comencement of the satelite system was constructed prior to aprox. 1970 .

as for being issued a "citation" and/or $$ fine , or a prosecution , I really don't know how individual cases would be or have been handled regarding non-compliance with FCC regulations ... I wouldn't want to find out about that the hard way personally .

ed: ... anyway , I hope some of what I have added to this topic is pertinent and useful ... I sorta stepped in headfirst only because of the "more serious" nature of the subject and the life threatening aspect of Emergency Locator Beacon usage .

instead of SPOT
I’d recommend a 406 PLB for paddlers who want to carry an emergency beacon. They’re small enough to wear, and cheaper than a full-size EPIRB.

Personally, I don’t see the need for one unless you’re on a very remote expedition. Virtually all of the US coast has tall USCG antennas monitoring 16, and they’ll hear a handheld VHF distress call anywhere that I have paddled.

PLB has multiple meanings
I’ve seen the term “PLB” used to refer both to small 406 EPIRBs that can be worn by a person, AND to 121.5 locator devices that are activated if a crewman falls overboard, to help the mothership find that crewman with a 121.5 handheld homing device.

These should really have different names, because they are totally different devices, but perhaps these are what you are seeing on the web Celia.