A comment on my article about PLBs asked what the primary differences between a PLB or EPIRB were. I thought putting some of the general differences down into an article would be a good response.


I say generally because, with each generation, some of the differences decrease – as technology advances the products can seem to become more similar in nature. I think the key difference lies in what that original intent of these devices was.


PLB or EPIRB? What is their purpose?

Primarily, both a PLB or an EPIRB is a device capable of transmitting its location to be picked up by satellite and radio systems – both systems are transmitting on 406 MHz which is picked up by the Cospas-Sarsat global satellite system.

Both are global devices – and this is important to remember. Even if you purchased your PLB/EPRIB overseas, provided you keep your registration details up to date, the amount of extra time that the information takes to get back to the appropriate rescue system should be minimal. However, this is why is it critical that these details are kept accurate.

The questions definitely needs to be not if I should have one, but which one is more appropriate to the situation.


PLB – Personal Locator Beacons

The PLB was designed to be a personal item – one what that carried on the individual at all times, as a result, these are lightweight, often now as big as a cellphone, require manual activation, and will have a minimum of 24 hours of battery life. While they may float, not all are going to. These are registered to an individual person.


EPIRB – Emergency Position-Indicating Radio Beacon

EPIRBs are generally expected to be permanently attached to a vehicle – be it a boat, yacht, aeroplane or otherwise. As a result, they can be a little larger, but with that comes more features – many units will automatically active if they get wet, and the minimal battery life for an EPIRB is 48 hours. Larger, more powerful flashing beacons are another common feature – as is the fact they will float. The EPIRB is registered to a specific vessel, not an individual.

So which one should I get?

Depends on their use. Is it a personal device for tramping and the like? A smaller PLB is likely to be more practical. Got a new boat and heading way out to sea? Then an EPIRB is a requirement.

A little more info…

A reader adds…

“The EPIRB equivalent for aircraft is called an ELT. Same thing but they are designed to interface directly with aircraft systems in addition to the standard beacon functions.

It is also worth noting some more advanced EPIRBS have the capability to define the type of emergency on the vessel depending on whether the EPIRB is using the long or short message format and/or location messaging protocol or national messaging protocol. No matter the message format or protocol COSPAS SARSAT accept all of them as defined in the T01 document.

Also with the introduction of the new MEO SARSATs, it means that they can obtain a Doppler position to reference against GPS position on the first satellite pass. “