Summary
The guide to emergency beacons
It is essential to go to sea with reliable and essential safety devices. These include, among others, the VHF, the life raft, the lighting system, and, what will interest us today, the emergency beacon.
The distress beacon, or rather, I would say "the" distress beacons. Indeed, we will see, in this article, thatthere are several kinds of distress beacons (EPIRB, PLB, MOB, with AIS, GPS) operating on different principles (radio or satellite frequencies) and complementary technologies.
Differences that are sometimes difficult to identify and a choice that is even less obvious. So, what is an emergency beacon? How do you choose your emergency beacon? What type of beacon is right for you?

The guide to buying a beacon
It is essential to go to sea with reliable and essential safety devices. These include, among others, the VHF, the life raft, the lighting system, and, what will interest us today, the emergency beacon.
The distress beacon, or rather, I would say "the" distress beacons. Indeed, we will see, in this article, thatthere are several kinds of distress beacons (EPIRB, PLB, MOB, with AIS, GPS) operating on different principles (radio or satellite frequencies) and complementary technologies.
Differences that are sometimes difficult to identify and a choice that is even less obvious. So, what is an emergency beacon? How do you choose your emergency beacon? What type of beacon is right for you?
What is an emergency beacon?
What is the purpose of an emergency beacon?
The emergency beacon is a safety device used to warn maritime authorities, rescue services, sea users or crew members of damage to your vessel, a capsize or a man overboard. In short, the beacon is the last link to the outside world in the event of a wreck or accident.
It can be fixed and affiliated to a boat, or portable and personal to each crew member.
As we will see later, beacons can operate either by satellite or by VHF (via a digital signal AIS), but they all share the same principles: to warn of an incident and to provide information on its position in order to facilitate searches.
How is the alert and rescue process organized?
As you can see on the diagram below available on the French Beacon Registry website, the alert and rescue process follows a very precise course as soon as your beacon is triggered.

- The fixed beacon emits a distress signal.
- The satellite network receives the 406 MHz signal
- The satellite sends an alert to a ground receiving station of the Cospas-Sarsat program.
- The alert is then routed to a Mission Control Center or MCC.
- The latter will exchange with the local emergency coordination center.
The best EPIRB beacons

EPIRB3 distress beacon
The new EPIRB3 RescueMe beacon from Ocean Signal is a manually-activated global rescue beacon incorporating a number of cutting-edge technologies that make rescue operations considerably easier .
The battery lasts up to 10 years, and the GPS features 72 channels for ultra-fast positioning. Other functions include a transmitter AIS, RLS (Return Link Service), strobe lights and connection to a smartphone via NFC.

GlobalFix V5 beacon (Cat. II)
Increase your chances of rescue with the all-new ACR GlobalFix V5 (Cat. 2) beacon. It's a manually triggered EPIRB (Emergency Positioning Radio Beacon) designed to transmit a distress signal for worldwide rescue.
These include a 72-channel multi-constellation receiver (GPS, Galileo, & Glonass GNSS) for ultra-fast positioning, a transmitter AIS, RLS (Return Link Service), strobe lights and connection to a smartphone via NFC.
What are the different types of beacons?
EPIRB and PLB distress beacon
As you may have seen in the maze of the Internet, there are several types of beacons. We will first distinguish the two main ones:
EPIRB, or Emergency Position Indicating Radio Beacon. These are the fixed distress beacons that are mandatory on all boats in offshore navigation, often fixed on a hydrostatic release.
This type of beacon is affiliated to a single vessel, whose MMSI number is entered in the beacon.
They generally have an automatic triggering on contact with water but can also be triggered manually, with an autonomy of 48 hours. EPIRBs are floating and waterproof.

PLB, or personal locator beacon. This time, the beacon is not necessarily linked to a vessel and its MMSI number, but contains the personal data of the wearer, attached to his or her lifejacket.
More compact, its autonomy is also weaker, with 24 hours of load. It also transmits on 406 MHz and 121.5 MHz.
These two formats of beacon have however a very similar mode of operation and can be equipped with various functionalities such as GPS orAIS.


MOB beacon (or AIS)
A third type of distress beacon is available on the safety at sea market: the MOB beacon, or "man overboard".
This personal distress beacon uses AIS technology to signal a man overboard. It is usually worn on the life jacket. The AIS system is a digital signal transmitted through the VHF. Many information can be provided to the receiver, such as position, heading, speed. Thanks to the onboard GPS technology, this data is very accurate. Once triggered, the signal can be seen by all vessels around equipped with a receiver AIS, with a range of approximately 5 miles.
The interest of the MOB beacon is the possibility of coupling it with its own system AIS and MOB. To make it simple: you have, for example, a fixed VHF AIS. It will then be able to alert you of the passage overboard of a sailor or a passenger, while indicating the information to the autopilot, which will in turn be in a position to carry out a man overboard maneuver. Similarly, a kill switch can respond to the distress signal AIS and stop the engine so that it does not move away from the wreck.
Difference between types of beacons
EPIRB |
PLB |
MOB |
|
---|---|---|---|
Transmitted signal |
Satellite 406 / 121.5 MHz |
Satellite 406 / 121.5 MHz |
AIS (& GPS depending on model) |
Autonomy |
48 hours |
24 hours |
24 hours |
Identification |
MMSI |
MMSI and/or Personal Code |
MMSI and/or Personal Code |
Scope |
All over the world |
All over the world |
5 miles |
How does an emergency beacon work?
Trigger
The triggering modes of the beacons diverge somewhat depending on their nature.
- The fixed beacon, or EPIRB, is automatically activated when you are submerged: at a depth of 3 meters, the signal begins to emit. However, it can be activated manually.
To know: The fixed beacons are generally proposed with a hydrostatic release, it is a box which contains the beacon. If the user cannot reach the EPIRB during a sinking, it is automatically released from its box via the hydrostatic release once it reaches a certain depth.
- The personal locator beacon, or PLB, is usually triggered manually (some models offer a trigger when the vest is inflated).
- The MOB beacon is automatically triggered when a man overboard is detected.

Issue
EPIRB or PLB beacons transmit on two frequencies simultaneously: 406 MHz and 121.5 MHz. Both have a different purpose, a different range and are not received by the same receivers.
The 406 MHz frequency emits a signal that is picked up by the Cospas-Sarsat satellite network. This global network then sends the distress signal back to a ground station, which then transmits to the coordination center. For a beacon not equipped with a GPS chip to be located after reception of the distress signal by a satellite, it will be necessary to wait for the reception of this same message by other satellites in the network in order to proceed with a triangulation. GPS is therefore a real time saver for localization.
The 121.5 MHz frequency is accessible to nearby buildings and aircraft (planes, helicopters). It will allow a more precise localization, reducing the search perimeter. This frequency is used during rescue operations.
The best PLB personal emergency beacons

Personal tag RESQLINK RLS
The ResQLink EPIRB , available with or without display, allows you to send a distress signal at any time and to know that it has been received (EPIRB = RETURN LINK SERVICE).
The beacon locates you using GPS positioning, a powerful 406 MHz signal and radio guidance on 121.5 MHz. The ResQLink 410 EPIRB (without display) or ResQLink View EPIRB (with display) quickly and accurately transmits your position to a global network of search and rescue satellites.

Personal Bivy Stick
Whether you're on the open sea on your boat, fishing in a river, hiking in the wilderness or doing a sporting activity far from everything, you can turn your cell phone into a satellite communication device thanks to the Bivy Stick!
As the leader in rescue products for professional and recreational use, ACR's Bivy Stick brings the safety and peace of mind of affordable and reliable satellite communication to everyone.
Which beacon to choose?
You will have understood by now, in order to increase your safety at sea, it is not enough to carry the minimum mandatory equipment, but it is wise to combine several devices and especially to adapt them to your marine practice.
Which beacon to choose for basic and coastal navigation?
In these navigation areas, the beacon is not mandatory, but damage can occur or a crew member can go overboard. As these are particularly busy areas, you will come across other vessels and shore-based receivers potentially in range.
In this navigation program, the EPIRB is not mandatory. Knowing that the rescue can intervene more quickly, the autonomy of a PLB beacon seems sufficient, however the delay to trigger a rescue operation can be long.
In this case, the beacon AIS, or MOB, seems to be the best option. Nearby boats equipped with a AIS receiver (on VHF for example) can intervene quickly.

Which beacon should I choose for semi-offshore and offshore navigation?
As a reminder, between 6 miles and 60 miles, we are sailing insemi-offshore: the beacon is not mandatory. It becomes compulsory when we exceed 60 miles and move to offshore navigation. Then, the EPIRB beacon is necessary. With this beacon, the distress signal can be received regardless of your position on the globe, including at the poles. Here again, it should not be sufficient on its own and can be supplemented by the use of a personal beacon.
In this context, we can highlight two cases:
- You are sailing in a fleet or with a crew: a system AIS seems particularly suitable. A vessel is less than 5 miles away and can intervene with precise GPS geolocation information.
- You are sailing alone and you have fallen overboard: vessels capable of receiving your signal AIS are not necessarily in your transmission zone, so no one will receive your call. The PLB beacon is therefore absolutely essential.

Beacons at Comptoir Nautique
Comptoir Nautique, Europe's leading marine electronics specialist, offers a wide range of beacons. Here we will be able to illustrate some of the configurations we have discussed above.
MOB beacon and alarm system AIS
A beacon AIS is only effective if receivers are nearby. In case the boat is not equipped with a VHF AIS, it can be judicious to associate a beacon and an alarm. For example, the personal beacon AIS MOB1 to the alarm box AIS MOB from Ocean Signal. This set will allow you to connect all the beacons of your crew (up to 10).
The man overboard alert will be triggered and will display a visual and audible signal to alert the boat's occupants. A perfectly efficient system that can connect to the NMEA network and communicate with all your instrumentation.

The best MOB personal emergency beacons AIS

MOB beacon AIS TB-520
The AMEC TB-520 distress beacon can be activated either automatically by the water sensor or manually through a quick and easy manipulation. An alert message is then sent to all nearby receivers with your GPS position and a unique identifier. The beacon's high-performance GPS receiver allows you to be located quickly and accurately.

EPIRB1 Pro beacon + GPS
For offshore navigation, the EPIRB distress beacon makes sense. However, the only emissions on the 406 and 121.5 MHz frequencies can limit the speed of intervention of the rescue services. This is why we offer the EPIRB1 PRO beacon with GPS.
The addition of the GPS protocol allows very precise location data to be transmitted by satellite, thus avoiding triangulation by several satellites of the Cospas-Sarsat program. Rescue operations can be triggered more quickly.
CONCLUSION
make your choice
Apart from the legal obligation to carry an EPIRB beyond 60 miles, it is difficult to draw a general rule concerning the choice of the type of beacon you should carry. However, we now know that this choice depends essentially on your navigation program and that the multiplicity of devices is the key to increased safety on board your boat. It is therefore prudent to have personal beacons for each crew member, in addition to a fixed beacon.
Our team of experts can be reached to answer all your questions, whether they concern beacons or simply prices, available stock or delivery times. You will find, of course, the best prices on comptoirnautique.com.