A Guide to Safety Beacons (PLBs, EPIRBs & AIS Beacons)

Emergency location beacons are fast becoming essential items of safety equipment that everyone should have on board. The cost of these devices has fallen dramatically over the last few years, so now is a great time to add some peace of mind to your next adventure. With such a vast range of models on the market, however, which is the right one for you?

See our guide below for the different types of safety beacons available and which is best for your needs.

 

What is an EPIRB?

An Emergency Position Indicating Radio Beacon, or EPIRB is a device carried on a vessel which can alert Search and Rescue to your location in the event of an emergency.

EPIRBs are registered to your vessel and once activated they send a coded message via the 406 MHz distress frequency which is relayed via satellites to Search and Rescue. This gives the beacon worldwide cover.

All the EPIRB’s we sell have built in GPS receivers which send out your position as well. This then gives a location accuracy of under 100m.

In addition EPIRB’s have a 121.5 MHz homing beacon. Rescuers use this when they are in the right area to pinpoint your exact location. 

McMurdo Smartfind G5          Ocean Signal EPIRB1

 

What is a PLB?

‘PLB’ stands for Personal Location Beacon. It is a device that can be used in life or death emergency situations to alert Search and Rescue services to your location.

Once activated it sends a message via the 406 MHz distress frequency which is relayed via satellites to Search and Rescue. This gives the beacon worldwide cover.

All PLBs that we sell have built in GPS receivers which send out your position encoded into the 406 MHz frequency. This then gives a location accuracy of under 100m.

In addition PLBs have a 121.5 MHz homing beacon. Rescuers use this when they are in the right area to pinpoint your exact location.

 McMurdo Fastfind 220 PLB       Ocean Signal RescueMe PLB1

 

Difference between PLB and EPIRB

Unlike EPIRB’s a PLB is registered to an individual person and not the vessel. This means that Search and Rescue will know exactly who is in distress and can take appropriate action. This makes it ideal for individuals who move between vessels or enjoy other land based activities.

PLB’s can only be activated manually whereas EPIRB’s are manual and automatic (water activated).

Once activated a PLB will transmit for a minimum of 24 hours, all the time the battery is in date. An EPIRB will transmit for at least 48 hours.

 

What is an AIS Beacon?

An Automatic Identification System (AIS) is an automatic tracking system originally designed for vessels to aid in collision avoidance. Now the same technology has been adapted to help in ‘man over board‘ (MOB) situations. Because of this, you might often hear them referred to as AIS Man Overboard (MOB) devices. 

An AIS beacon, once activated, transmits an MOB message to AIS equipped vessels within range (approx. 4-5 miles). A built in GPS receiver ensures that your exact location is sent.

This is then displayed on a chart plotter or other screens that have an AIS interface as an MOB icon.

Most AIS beacons are designed to be fitted inside a lifejacket and will activate automatically upon inflation.

McMurdo Smartfind S20 AIS          Ocean Signal MOB1 AIS 

  

Do I buy an AIS beacon or PLB?

We are often asked this question and is hard to answer. This is primarily because the two devices have a very different purpose. AIS beacons are primarily designed for MOB rescue, whilst PLBs alert the emergency services to a life or death situation.

In a 'man overboard situation' the first thing to consider is who is most likely will be to rescue you? The best chance of rescue is usually from your own vessel. An AIS beacon would be more suited for this situation, as it will alert your own boat or boats within range.

Single handed sailors would probably benefit more from a PLB to contact the emergency services, especially if there are no other vessels within range.

Also, if you want to be able to see AIS MOB on your vessel you will need to have an AIS system on board.

Neither device has a subscription fee, although you are required to register the PLB with your local authority.

 

Model Comparison Table

Beacon Type EPIRB PLB AIS Beacon
Make / Model  McMurdo G5 Ocean Signal EPIRB1 McMurdo 220 Ocean Signal PLB1 McMurdo S20 Ocean Signal MOB1
Battery Life (Standby) 6 years 10 years 6 years 7 years 7 years 7 years
Minimum Operation Time 48 hours 48 hours 24 hours 24 hours 24 hours 24 hours
Dimensions D x W x L (mm)* 115 x 108 x 225 89 x 89 x 178 34 x 47 106 32.5 x 51 x 75 27 x 47 x 124 27 x 38 x 134
Weight (grams) 770 422 152 116 120 92
Activation Auto & Manual Auto & Manual Manual Manual Auto** & Manual Auto** & Manual

*Smallest stowed dimensions

**When fitted correctly in lifejacket