Comparison · Updated July 2026

EPIRB vs PLB

Both are 406 MHz distress beacons on the same free government satellite network. The difference is who they belong to, and it decides which one you need.

Short answer

A boat needs an EPIRB registered to the vessel, and every crew member should carry a PLB. Both send a 406 MHz distress signal to the free Cospas-Sarsat network, so either one reaches rescue directly with no subscription. The EPIRB is bigger, floats, can self-activate, transmits for 48+ hours, and is what you grab when you abandon ship. The PLB is pocket-sized, clips to your life jacket, and covers a person overboard, when the EPIRB is still on a boat that sailed on without you. Offshore, you want both; a coastal day boater can start with a PLB each.

EPIRB vs PLB, side by side

	EPIRB	PLB
Registered to	The boat (vessel)	The person
Distress network	406 MHz Cospas-Sarsat (free, government)	406 MHz Cospas-Sarsat (free, government)
Activation	Manual, or automatic when it floats free (Category I)	Manual only
Size	Larger, lives in a bracket on deck	Pocket-sized, clips to your PFD
Battery (operating)	At least 48 hours transmitting	At least 24 hours transmitting
Battery (storage life)	About 10 years	About 6 to 7 years
Floats	Yes, designed to float antenna-up	Most do not float on their own
Best for	Abandoning the boat, the whole crew at once	Person overboard, and off the boat too

Which one do you need?

Get an EPIRB if you leave sight of land, sail overnight, or ever cross open water. It is the beacon that stays with the boat and covers everyone aboard the moment you abandon ship, and it is the piece a delivery skipper or offshore rally will expect to see. On many boats it is also the only distress device that can activate itself if the boat goes down before anyone can reach it.

Get a PLB for each crew member because the EPIRB does you no good if you go over the side and the boat keeps sailing. A PLB on your life jacket is the one beacon that is physically on you when it matters, and because it is registered to you it works ashore too, hiking or in the dinghy.

The honest floor: a coastal boater who never loses sight of shore can start with one PLB per person and skip the EPIRB until they range farther. Anyone going offshore carries both, and neither one is a satellite communicator, which sends its SOS to a paid private call center rather than the free government network.

Our pick of each

For the boat, the ACR GlobalFix V5 AIS is the EPIRB we would buy: a 406 MHz beacon with a built-in AIS transmitter and a user-replaceable 10-year battery. For the crew, the Ocean Signal rescueME PLB1 is among the smallest in its class with a 7-year battery and a guarded button. Full picks, prices, and the runners-up are in the guide.

See our full EPIRB & PLB picks →

How we are paid: the guide contains affiliate links, and if you buy through them we earn a commission at no extra cost to you. It does not change what we recommend.

Common questions

What is the difference between an EPIRB and a PLB?

Both are 406 MHz distress beacons that reach the same free Cospas-Sarsat government satellite network, so either one summons search and rescue directly. The difference is registration and role: an EPIRB is registered to the boat, is larger, lives in a bracket, floats, can self-activate when it hits the water, and transmits for at least 48 hours; a PLB is registered to a person, is pocket-sized, clips to a life jacket, is activated by hand, and transmits for at least 24 hours. The EPIRB is for abandoning the vessel; the PLB is for a crew member, including off the boat.

Do I need both an EPIRB and a PLB?

For any boat that goes offshore, yes, and they are complementary, not either/or. The EPIRB stays with the boat and covers the whole crew if you have to abandon ship; a PLB goes on each crew member and covers a person overboard, when the EPIRB is still bracketed on a boat that just sailed away. Coastal day boaters who never leave sight of shore can often start with one PLB per person and add an EPIRB as they range farther.

Is EPIRB or PLB registration free, and is it required?

Registration is free and required. In the US you register a 406 MHz beacon with NOAA at no cost, and it is a legal requirement that also gives rescuers your details the moment the beacon fires. Unlike a satellite communicator, there is no monthly subscription for the distress function of an EPIRB or PLB, because the Cospas-Sarsat network is government-run.

Is a satellite communicator like a Garmin inReach the same as a PLB?

No. A satellite communicator sends its SOS to a private call center on a paid subscription, which then relays to rescue services; a PLB sends a 406 MHz distress signal directly to the free government Cospas-Sarsat network with no subscription. A communicator is great for two-way messaging and lower-stakes check-ins, but for a genuine life-threatening emergency the registered beacon is the primary tool. Many cruisers carry both.

How long does an EPIRB or PLB last before it needs service?

The battery has a storage life of roughly 10 years for an EPIRB and about 6 to 7 years for a PLB, printed on the unit as a replace-by date; that is separate from the operating time once activated (at least 48 hours for an EPIRB, 24 for a PLB). When the storage date is up you replace the battery, or on cheaper units the whole beacon.

More of the counterintuitive marine numbers in one place: Boating by the Numbers.