Guide to Personal Locator Beacons

Most outdoor enthusiasts travel to the wild to escape technology and the stressful modern world to relax in the serenity and simplicity of nature. Backpacking in the wilderness is deeply rewarding to the soul, but it also entails risks that can be life-threatening, even for the most experienced adventurers.

When going to these places, communication devices become all the more important. When traveling the vast hinterlands and expanses of wilderness in the lesser-inhabited places in the world (or even some rural areas of well-connected countries), the connection becomes trickier. Some need more routine contact with the outside world, like for instance, people going for a day-long hike on difficult mountains and terrain.

When you can’t rely on smartphone and cell signals, personal locator beacons and satellite messengers become vital. Personal locator beacons (PLBs) are satellite-based handheld devices that act as a safety net for travelers, while satellite messengers are a more recent innovation that offers backcountry communication options. This guide will focus on personal locator beacons.

What are personal locator beacons?


Available in the US since 2003, personal locator beacons (PLBs) are a type of emergency location device used by outdoor enthusiasts to be ensured that assistance will arrive in case of a crisis critical to survival. These are handheld, high-powered devices designed primarily to send out a personalized emergency distress signal. They are the land-based equivalents of Emergency Position Indicating Radio Beacons (EPIRBs), which has been used for decades in marine environments. PLBs are also called as distress radio beacons, emergency beacons, emergency locator transmitter (ELT), or other similar terms.

While a PLB is a must-have when you’re a regular traveler to the wilderness or to any places that are hard-to-reach by phone signal, you’d wish you will never have to use it. It is because PLBs should only be activated in situations of grave and imminent danger – only as last resort when all means of self-rescue have been exhausted. Why? You’ll learn later.

What do I need to know before buying a PLB?

A PLB is a very simple system since it acts as an alert during life-threatening situations. All it does is to broadcast your location so you can be rescued by either of these rescue agencies: United States Coast Guard (USCG), National Oceanic and Atmospheric Administration (NOAA) and Air Force Rescue Coordination Center (AFRCC). It’s the most reliable system with the best chance of getting rescued if something goes terribly wrong. Though it’s simple, you have to read the instructions for use that you can also find online at for free and really easy to use ,but do that before you leave your home. You don’t want to be fumbling with a notice while you’re hanging from the edge of a cliff or top of a tree.

Here are other things you must know about PLBs:

  • It doesn’t work as a phone. You can send a message, text or call using it.
  • Once something terrible happens and you have activated your PLB (but I hope it won’t happen), the device continues to broadcast a signal for at least 24 hours, even in places with the coldest temperatures.
  • Most batteries for PLB can last up to 5 years.
  • It needs a clear view of the sky to work effectively. Like GPS, it needs a direct line of sight to the satellite.
  • Not all PLBs have GPS, but it’s best to get one that has it. PLBs without GPS can work, but the signal without GPS coordinates won’t be as precise as PLBs with one.
  • PLBs are easy to carry. They almost always come with a hand tag for easy handling, and it’s about the size of an old-fashioned cellphone.
  • PLBs are expensive but don’t be tempted to buy a second-hand device. It may be costly to change old batteries, or it may be obsolete.  If you’re a solo traveler and you don’t own one yet, you can put it on your wish list for your next birthday.
  • A PLB is only an alert device. Any expenses for your rescue isn’t covered by the purchase of this device, so make sure you get travel insurance.

How does a PLB work?

No matter where you are in the world, a PLB can activate a powerful signal at 406 MHz, which is an internationally recognized distress frequency monitored in the US by USCG, NOAA, and AFRCC. Also, it sends a homing frequency of 121.5 MHz. The 406 MHz frequency from the satellite will get rescuers to within 5 kilometers of your position. The search and rescue teams will use a tracking device to hone in on the frequencies.

To make it more detailed, here’s how it works: those signals are sent to a network of American, Canadian, French and Russian weather and global navigation system satellites that are part of the international COSPAS-SARSAT satellite-based search and rescue system. “COSPAS” is a Russian acronym for Space System for Search of Distress Vessels, and “SARSAT” means Search and Rescue Satellite-Aided Tracking. It is a global network of satellites especially configured for search and rescue communication and positioning. COSPAS-SARSAT uses a constellation of satellites called MEOSAR (Medium Earth Orbit Search and Rescue), allowing for near-instantaneous detection of the PLB signal. These satellites can locate the PLB without the GPS-encoded information.

Once they have received your transmitted signal, the satellites “fix” on your location using frequency of arrival and time of arrival methods. This information will be related to the USCG and AFRCC, depending on your location. If your PLB is GPS-compatible, it can deliver your GPS coordinates to the search and rescue personnel through the satellite system. It will be passed on to the local search and rescue authorities who will come and assist you. Now you know why PLBs should only be used in a life-threatening situation. False alerts endanger others’ lives and can cause expensive disruption to search and rescue services. Also, it is illegal to activate PLBs in a non-emergency situation.

According to COSPAS-SARSAT regulations, a PLB must transmit for this amount of time:

  • A class 1 battery must be able to transmit at -40 degrees Fahrenheit for 24 hours.
  • A class 2 battery (which most recreational PLBs use) must be able to transmit at -20 degrees Fahrenheit for 24 hours.

These temperatures represent worst-case scenarios in cold places. Batteries will operate for twice as long in warmer areas, like for instance, a place with a temperature of 70°F.

PLBs are equipped with a long-lasting lithium battery, which remains dormant until you activate the PLB. Keep in mind that it’s best to have a visual or audible distress signal such as a strobe light, signal mirror or whistle to help catch the attention of the search and rescue team when they are getting close. This is why many PLBs have a built-in LED signal light for this purpose.

Since PLBs are personal gadgets, federal law requires it to be registered in your name in the NOAA SARSAT database. This is free of charge and the data is protected and only shared with rescue forces when the PLB is activated. When you register, NOAA will link your essential information to a 15-character code called the Unique Identifying Number (UIN). The UIN tells personal information you’re your name, address, phone number and any medical conditions you may have. Once your PLB is activated, your UIN will be transmitted to the COSPAS-SARSAT satellites via electronic bursts. You can register your device or update your personal info at

How does PLB differ from satellite messengers?

You may have mistaken a PLB with a satellite messenger. Like PLBs, a satellite messenger is a handheld, signal-transmitting device that is useful for areas far from reliable cell phone coverage. These devices allow you to communicate your location coordinates and/or send short text messages to friends or family back home so you can report on your trip’s status or send calls for help. This is a casual tool that transmits signals that are less powerful than a PLB signal, and these are not recommended for serious mountaineering use.

Satellite messengers are devices that rely on either two of commercial satellite networks such as Globalstar (used by SPOT devices) and Iridium (used by DeLorme devices) – rather than the military-based COSPAS-SARSAT networks.

Satellite messengers are cheaper to buy than PLBs, but you have to pay subscription fees in order to use it.

In conclusion, if you’re a serious, daredevil adventurer who’s concerned about being rescued in case of dire situations, getting a PLB is best for you. If you want to stay in touch with the world as you go on adventures, a satellite messenger can be more useful.

What are the best personal locator beacons?

There are only a handful of trustworthy personal locator beacons you can find on the market, and here are some of them:

Where to Buy
ACR PLB-375 ResQLink+
ACR Aqualink View
Ocean Signal rescueME PLB1
Artex PLB
Microwave Monolithics MicroPLB GXL
McMurdo Fast Find 220 PLB

1. ACR PLB-375 ResQLink+

The ACR PLB-375 ResQLink+ is a solid choice for many outdoor adventurers like hikers, climbers, campers, and hunters. It’s a basic PLB with all the features you’ll need for ensuring that rescuers can come quickly to reach you during life-threatening situations. Besides the 406 and 121.5 MHz transmitters, the ResQLink+ also includes an internal GPS interface, a bright LED emergency strobe light, and a great lithium battery. Its small size (it’s smaller than a lot of smartphones) and lightweight of fewer than 6 ounces, it makes handy insurance for your life. ACR can also replace the unit for free, in case you need to use it. They will add your used unit to their “wall of fame” and send you a new one.

2. ACR Aqualink View

ACR Aqualink View is a lot similar to the ResQLink+, but this one has notable advantages. This PLB floats, so if you need it for water activities like over-water flying, water rafting, kayaking and the like, ensuring that the PLB won’t end up at the bottom of the lake or ocean. It has a built-in floatation and waterproofing for water accidents. Another advantage this PLB has with the earlier mentioned is that it has an LED digital display that makes it easy to use. Through the screen, you can follow instructions, check battery life, view GPS latitude and longitude, and receive information directly instead of trying to decipher beeps and LED flashes. It also has a built-in strobe light and GPS.

3. Ocean Signal rescueME PLB1

Ocean Signal rescueME PLB1 is a compact and affordable PLB with a seven-year battery storage life. It’s almost half the size of ACR’s PLBs, making it one of the smallest satellite-linked PLBs in the world. This handy PLB is equipped with 66-channel GPS and a bright strobe light for easy visibility in dark places. It also comes with a floatation pouch to make it usable during dire situations where you’re in the water and a mounting clip on the body for easy clipping on your jacket or life vest.

4. Artex PLB

Artex PLB looks a lot like Ocean Signal’s unit. Its ultra-compact design makes it easily fit inside a pocket or attached to a belt through its mounting clip. It has seven-year battery life and a matching seven-year warranty. It can be easily operated with one hand and has a two-step activation process to prevent unintentional activation. This PLB is equipped with a 66-channel GPS receiver and a high-intensity strobe light.

5. Microwave Monolithics MicroPLB GXL

Claiming to be the smallest and lightest-weight PLB in the world, Microwave Monolithics MicroPLB GXL has been in use by US government agencies for more than 14 years. It has internal GPS, but it does not have a strobe light. It makes up for this by being so small and light, and by having one of the best batteries of any PLB units in the market – designed to last for continued transmission for at least 48 hours. In a manufacturer field testing, the battery of this unit continuously transmitted for five and a half days. What an impressive feat for such a small PLB.

6. McMurdo Fast Find 220 PLB

A basic, lightweight PLB, McMurdo Fast Find 220 PLB is a beacon worth considering. It’s a slim unit that can easily fit in a shirt pocket or flight bag. The unit is waterproof to a depth of 10 meters, and comes with a buoyancy pouch that can keep it afloat. Its antenna is securely stored but deploys quickly when activated. It has a bright SOS flashing LED light that can help rescuers locate you in dark places.