Everything You Need to Know About Personal Locator Beacons and Satellite Communicators

Learn how different devices work and choose the best one for you. In this guide, we review PLBs and one- and two-way satellite messengers.

Nobody ever wants to have to call for help on an adventure. But when you do need a hand—whether it’s because you missed a turn and can’t find your way back or because you took a tumble and broke a leg—you’d better make sure whatever lifeline you have works.

That’s where a personal locator beacon (PLB) or satellite communicator comes in. Whether you’re in the middle of the Atlantic Ocean or deep in a Utah canyon, a network of satellites is ready to hear your call for help.

But not all units are made alike. Some devices do nothing more than SOS, while others let you keep in touch with and reassure friends and family off the grid, and still others bundle a full comms hub with precise GPS capabilities and even a camera to create a single all-in-one device.

Read on to figure out which unit is best for you.

Garmin InReach Mini
The original Garmin inReach Mini in the field. As of February 2022, the pocket-size Mini 2 ($400) is available.

How do personal locator beacons and satellite communicators work?

PLBs and satellite communicators rely on a network of—you guessed it—satellites that rove in space. Since these constellations of satellites are spaced out in orbit, users almost always have enough hardware overhead to get a message out (the specific satellite networks vary device to device). That makes them far more dependable than your smartphone, which uses cell towers that often aren’t accessible when you’re in the backcountry.

Shop all PLBs and satellite communicators.

Personal Locator Beacons

The most basic emergency tool is a personal locator beacon, or PLB. It operates like an EPIRB, or Emergency Position Indicating Rescue Beacon, on a boat, allowing you to SOS, or alert search-and-rescue services, with the push of a button. Think of it like 9-1-1 when you don’t have cell service.

When that button is pressed, a signal is beamed up to the satellite network and then relayed to a dispatch with your location and information and forwarded to the proper authorities (local law enforcement, search and rescue, the Coast Guard or whoever is responsible for lending you a hand). To activate the device, you unfold the antenna, press the button, then wait for help.

One such PLB is the ACR Electronics ResQLink View ($379.95). It has a five-year battery life, so—assuming you don’t activate it—it should serve as a ready-to-go insurance policy on half a decade’s worth of trips. It also uses government satellites (so you don’t need a subscription) and should alert authorities to within 100 meters of your position. This one has a battery life of over 24 hours, so you may continually broadcast your location to rescuers if you’re moving.

The downside: PLBs like the ResQLink View send out your location and personal information, but that’s it. There’s no confirmation that the message was received, there’s no ability to send different or custom messages, and you won’t receive a message in return. But their simplicity still makes them a popular option for adventurers who simply want the function to SOS in a bad situation.

Shop all PLBs.

ACR Electronics Bivy Stick
To use the ACR Electronics Bivy Stick ($199.95), you need to pair it to a smartphone.

One-way and Two-way Messengers

If you desire to do anything more than SOS, you should look into a one- or two-way satellite communicator, which is a device that, at minimum, can track your location and fire off messages. Such units’ capabilities in both areas—as well as feature sets—vary widely.

Shop all satellite messengers.

One-way satellite messengers

One-way satellite communicators take PLBs to another level, allowing the user to send a specific message. These units use private satellite networks and therefore require subscriptions (kind of like cellphone plans).

Many of these devices allow you to easily send messages to friends and family, in addition to baseline SOS functionality. Typically, you customize your messages and contacts before heading into the backcountry, then select your text and recipient when you’re off the grid. This allows you to notify emergency contacts that you’re OK, that you safely arrived to camp, that you’re going to be one day longer than expected, that you need help getting your car unstuck from the trailhead lot, or any number of other updates short of SOS’ing. (No one can reply, however—hence “one-way” messenger.)

Take the SPOT Gen4 ($149.95). You can program up to 1,250 of messages and set it up to periodically send your location to a map that friends and family can view from home. But on devices like the Gen 4, once you hit SOS, that’s it. As with a PLB, it sends a signal to rescuers, without any context.

Plans for the SPOT Gen4 start at $11.95 per month.

Two-way satellite messengers

If one-way satellite communicators take PLBs to another level, then two-way satellite communicators take one-way satellite communicators to another level, allowing you to both send and receive messages. Those messages can be from the rescue dispatch or friends and family. There are two types of two-way satellite messengers.

Phone not required

Some two-way satellite communicators can function entirely on their own, much like PLBs and one-way devices. You do not need a phone or supplemental device to use these units. The pluses here are that you have fewer moving parts to remember, protect and keep charged. The negatives: The units tend to be bulkier, and certain functions—like typing out a custom message, for instance—can be more time-consuming, less intuitive and, well, annoying.

One of our favorite two-way satellite communicators like this is the brand-new Garmin inReach Mini 2 ($400). With this unit, you can send messages in the backcountry entirely through the device (or with a paired cellphone). You can even have text-message-like conversations while on your adventure. If you hit SOS, you can provide additional information to rescuers, and they can keep you updated on their progress or ask you to move to a more accessible location.

Backpackers will love that the palm-size Mini 2 weighs a scant 3.5 ounces. This iteration builds on the successful original with a beefed-up battery life, a higher-resolution display and new GPS features like an electronic compass and quicker satellite acquisition. Editor’s note: The Garmin inReach Mini 2 is available early to co-op members beginning February 2022.

If, however, you’re in the market for a full GPS unit and a two-way satellite communicator, opt for a five-tool player like the Garmin Montana 700i ($700). This superstar does it all with a large, 5-inch colorful display and a QWERTY keyboard that lets you easily type messages.

Subscriptions for Garmin devices like the inReach Mini 2 and Montana 700i start at $11.95 per month.

Phone required

A growing collection of two-way satellite communicators rely on the cellphone you’re probably already carrying in your pocket or hipbelt. Such devices cannot function without your smartphone’s keyboard and Bluetooth capability. As you might imagine, there are pluses and negatives here, too. Positives are that you are probably more familiar with your phone’s functionality and keyboard, anyway, and that the communicator itself can be ultrasmall and sleek. Negatives are that you need to keep track of two devices and ensure that they’re both charged and protected, as well.

One such two-way messenger is the 3.5-ounce ACR Electronics Bivy Stick ($199.95). This sleek unit pairs with your phone; the actual device has an On/Off button, a check-in button and an SOS switch—that’s it.

Data plans for the ACR Electronics Bivy Stick start at $14.95 per month.

ACR Electronics ResQLink View ($379.95), SPOT Gen4 ($149.95), Garmin inReach Mini 2 ($400), Garmin Montana 700i ($700) and ACR Electronics Bivy Stick ($199.95)
The ACR Electronics ResQLink View ($379.95), SPOT Gen4 ($149.95), Garmin inReach Mini 2 ($400), Garmin Montana 700i ($700) and ACR Electronics Bivy Stick ($199.95) are our favorite emergency communication tools.

The tools of the trade

There is a slew of different devices out there, all with different functions and specs.

DeviceTypeFeatures and SpecsPrice
ACR Electronics ResQLink ViewPersonal locator beacon– No separate subscription required
– Digital display
– Easy to use
– Battery has a 5-year shelf life
– 5.3 oz.
SPOT Gen4One-way satellite communicator– Subscription required
– Send SOS, Help Needed, I’m OK and a custom message with individual buttons (but no confirmation that messages were successfully sent or received)
– Can customize as many as 1,250 messages
– Tracking feature lets friends and family view your location at a specified interval on an online map
– 5 oz.
$149.95 (not including subscription)
Garmin inReach Mini 2Two-way satellite communicator (phone not required)– Subscription required
– Send SOS, preset messages and custom messages, either using the device’s menus or with a paired cellphone
– Receive messages, replies and weather reports, readable on the device’s screen
– Tracking feature lets friends and family view your location at a specified interval on an online map
– 3.5 oz.
$400 (not including subscription)
Garmin Montana 750iTwo-way satellite communicator (phone not required)– Subscription required
– Send SOS, preset messages and custom messages on the device’s full-color, glove-friendly, 5-inch touchscreen
– Receive messages, replies and weather reports, readable on the device’s screen
– Full suite of GPS features, including topographic maps, high-resolution satellite imagery, turn-by-turn navigation and a three-axis electronic compass and barometric altimeter
– Built-in 8-megapixel camera
– 14.5 oz.
$700 (not including subscription)
ACR Electronics Bivy StickTwo-way satellite communicator (phone required) – Subscription required
– Send SOS and preset messages on the device
– Send custom messages with a paired cellphone
– Receive messages, replies and weather reports, readable on a paired cellphone
– 3.5 oz.
$199.95 (not including subscription)