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How to Choose a Personal Locator Beacon

How to Choose a Personal Locator Beacon
The Explorer+ has a large display with a menu that is easy to navigate.
Credit: Jenna Ammerman
By Jediah Porter ⋅ Review Editor
Thursday January 19, 2023

Communication is key. This is a fundamental human truth. For wilderness adventuring, beyond the reach of a modern cell signal, connection is trickier. Many of us go to the wild to escape the tether of modern communications, but we also seek to mitigate the consequences of ill-fortune or poor choices. Some, of course, need more routine contact with the outside world for one reason or another. Enter the array of satellite messengers, personal locator beacons, and other backcountry communication technologies. We are here to guide you through your choices and demystify the options. We will walk you through a step-by-step process of choosing a device suited to your needs and wishes.

personal locator beacon - the inreach app lets you access backcountry satellite communication...
The inReach app lets you access backcountry satellite communication with front country convenience.
Credit: Jediah Porter

Types of Wilderness Communication

First, the confines of our discussion — we limit our discussion to those products and services that provide contact to the outside world, without cell signal, from the wild. We further limit our discussion to those devices and systems that provide digital, text-based communication. Voice transmission (as provided by satellite phones, two-way radios, and walkie talkies) is, paradoxically, less clear, more expensive, and complicated to execute. Sometimes, of course, it is the best choice. Here, we are discussing text-based communication. There exist devices and services that provide voice-only or all that a texting product does and more. Anything that includes voice is significantly more expensive and at least a little bulkier than the average text-only product. For human-powered, recreational, terrestrial wilderness adventures, you don't really need voice contact. If you do, you likely have connections and contacts that can help you choose.

Emergency Messaging

The simplest and arguably most important type of communication is the SOS message. Sending a message that contains your location, as deduced by GPS triangulation, and alerts a dispatcher to your need for help is the most common and least expensive sort of backcountry communication. An SOS message like this, regardless of which system it employs, conveys nothing more than your location and that you need help. This is, therefore, suitable only for “life or limb” emergencies. Transmitting more nuanced information about the nature of your emergency with an SOS message is impossible. Some devices, predominantly those using the COSPAS/SARSAT network, only perform SOS messaging.

In our review, the Ocean Signal rescueME PLB1 and ACR ResQLink View use the COSPAS/SARSAT satellite and dispatch system and offer little more than SOS functionality. All products in our test provide some level of emergency messaging.

personal locator beacon - these devices offer comparable access to the cospas/sarsat network...
These devices offer comparable access to the COSPAS/SARSAT network, the Ocean Signal is just half the size of the ACR ResQLink+.
Credit: Jediah Porter

Non-Emergency Messaging

What if you just want your loved ones to know that you are OK? The lack of an SOS message should be reassuring to your emergency contacts in civilization ("no news is good news"), but it isn't definitive. If something really, really bad happens, you may be unable to activate the SOS mode on your device. If this uncertainty is overly stressful to your loved ones, having the option to send an “I'm OK” message is of value — even better if that “I'm OK” message contains information about your location. Because the COSPAS/SARSAT network is for emergency use only (with rare, unique, virtually unheard of exceptions), equipment leveraging that technology is not suited to sending “OK” messages. Any device that sends an “OK message” must use a different civilian network.

SPOT Inc, with their flagship device, pioneered the widespread adoption of “OK” messaging in 2007. The SPOT device, now in its fourth generation, is a sort of industry standard and can be purchased, registered, and used to send both SOS messages and a couple of different types of “OK” messages. SPOT also now offers the SPOT X. The X does everything the SPOT Gen4 does, plus two-way messaging. Many other products on the market send some sort of “check-in” message. Notably, the tested Apple iPhone 14 is lauded for its Satellite Emergency SOS function. What hasn't been so prominent in the promotional materials is that, through Apple's “Find Me” app, one can manually send their location to loved ones via satellite. Implicit in such a message is that the user is able to send such a message. You and your loved ones watching along can decide on further interpretations/assumptions of such a location share. As you shop, and eventually configure your device, investigate whether that check-in message automatically includes location data or if it needs to be activated. Also, consider whether your chosen device and service require a smartphone to send an OK message or if one can be sent via the device itself.


Tracking is essentially a sort of automated “OK message”, sent, after initial activation, without your participation, and on some predetermined interval. Tracking data is sent to contacts you identify or to a web interface you can share in a variety of ways. Loved ones at home sometimes enjoy “watching” your progress. Satellite messenger live tracking is fast becoming a standard way of verifying speed records and “fastest known times”. Not all satellite messaging services and products offer live tracking. OK messages and tracking don't give any sort of customized or qualitative information about your progress or status.

Two-Way Messaging

What if, then, you want to send more nuanced information from the wild? “Body and minds are all well, but this flooding creek will delay our exit a day. Don't worry about us in the meantime”. This sort of targeted information is impossible with the preprogrammed “OK” message devices and systems. A device that can send a message like this, with no more advanced functionality, is currently theoretical. (There was once a SPOT device that could send customized messages from the field, but it isn't on the market any longer.) If you want to communicate in this manner, you need to look for two-way communication options.

In many cases, two-way communications are very helpful. Being able to request certain types of field weather and conditions information, for instance, is of great value. Regular, casual communication is very nice for maintaining all sorts of social and business relationships. Options for two-way texting from wild spaces are currently and rapidly increasing. Prices are coming down, and functionality is increasing. This is a great trend, and the state of the market now means that you can have two-way texting for equal to or less than the cost of prior, more limited options. Options and functionality are increasing, but products currently still all use the same existing, inherently limited satellite networks.

personal locator beacon - example of the inreach messaging when paired with a smart phone.
Example of the InReach messaging when paired with a smart phone.
Credit: Chris McNamara


There are two major questions you must be asking. We just discussed the main one. What sort of communications do you want and require? After that, the remaining consideration is coverage.

Communication Networks

There are a few different communication networks you must understand in order to understand your non-emergency messaging options. All of them can also transmit SOS messaging.

Public — COSPAS/SARSAT is the moniker for a global network of satellites explicitly configured for Search and Rescue communication and positioning. Devices made to access the COSPAS/SARSAT network do three things with the push of one button. Generally, these devices have just this one button to push, and just this one purpose to execute. Activating the SOS button of a COSPAS/SARSAT system PLB (Personal Locator Beacon is a phrase usually used to identify COSPAS/SARSAT devices):
  • First ascertains location with regular GPS triangulation.
  • Then sends that location, as well as your identifying information from the device and tied to your registration, to the COSPAS/SARSAT satellite network.
  • Finally, the device transmits a distress signal on a different frequency that can be received and position-located by aircraft.

Depending on your location and the country you registered your COSPAS/SARSAT PLB with, the emergency satellite message and associated location and identification information are transmitted through one of a few national Search and Rescue (SAR) dispatch organizations. That SAR dispatch organization (in the United States it is a subdivision of our national weather service, with cooperation from both the Air Force and the Coast Guard) then works to secure the most local and most effective SAR resources. The required PLB registration, emergency dispatch protocol, and resource acquisition that accompanies a COSPAS/SARSAT activation is a tax-payer-supported “free” service like municipal fire or law enforcement services. With COSPAS/SARSAT, both the communication network and the dispatch service are public services provided by the government.

personal locator beacon - in an emergency, find the clearest view of the sky you can, deploy...
In an emergency, find the clearest view of the sky you can, deploy the PLB1's antenna, and push SOS.
Credit: Jediah Porter

Private — The next type of emergency messaging is found in the private sector. Subscription-based devices and services employ one of a few commercial satellite communication networks and third-party dispatch services to simulate the COSPAS/SARSAT response. With these devices, adequately configured and subscribed, the user pushes an SOS button, and the device ascertains location with GPS signal and sends the info to a satellite and onto the ground. To this point, functionality is the same as on the COSPAS/SARSAT system. Devices using private-sector satellite networks do not transmit the secondary aeronautical distress signal. There are three major private-sector satellite networks. SPOT Devices and iPhone 14 use the Globalstar system of satellites (which is wide-ranging but not global), while Garmin, Somewear, and Bivy use the global Iridium satellite network.

The emergency message, with location and identity information embedded therein, is sent through a corporate dispatch office and on to local SAR resources. Device and service companies, without exception, contract out the monitoring and dispatch services. All private sector SOS messaging services (from Garmin, SPOT, Somewear, ZOLEO, and Bivy devices) contract one of three different private enterprises to handle monitoring and dispatch. Whether your SOS message is sent from a SPOT Gen4, Somewear Global Hotspot, or one of the other mentioned devices, it will funnel through GEOS, Garmin Response Team, Global Rescue, or Focus Point International. It will then be a dispatcher at that private enterprise that makes a phone call to a local SAR team.

personal locator beacon - the inreach explorer+ hanging out in its element.
The inReach Explorer+ hanging out in its element.
Credit: Chris McNamara

In other parts of the world and other sectors, there are even more communication networks, dispatchers, and protocols. These are just the main players in the United States.

Because of the currently limited selection, communication type and signal coverage are tied together. However, there are exceptions. Essentially, you have the choice of global satellite coverage or regional satellite coverage. For truly worldwide coverage, COSPAS/SARSAT and the Iridium network are the only viable options. Globalstar, employed by SPOT devices and iPhone 14, is one we would consider to be “regional.” It is entirely possible that the Globalstar network will cover everywhere you might travel.

How to Carry Your Important Compact Electronics

Most personal locator beacons or satellite messengers are equipped to clip to the outside of your backpack or clothing, which suggests that they should be. We don't recommend this. While GPS navigators are often clipped outside your pack because they work best when they have a clear view of the sky, your SOS device shouldn't necessarily be on at all times. You can feel comfortable turning it off and stowing it safely away, which lowers your chance of losing it. If you are tracking with your satellite device, it will work just fine inside the top of your backpack. We've tested all the tracking devices from inside our backpacks (always at or near the top) and have found little to no difference in tracking/messaging function.

Further, don't stress about it taking a little longer to dig the device out of your pack. The fact is, an emergency response will take hours at best. A few seconds to take your backpack off won't make any appreciable difference in the response time. Perhaps in those minutes, you will take a breath and realize that you don't actually need outside help. And worse than a few minutes of delay is losing your satellite messenger entirely. In summary, we don't recommend carrying your personal locator beacon or satellite messenger on the outside of your backpack

Service Plans and Subscriptions

All communication equipment that we tested needs to be registered somehow. Some are free, while some present piles and piles of paid options. These options will be ever-changing and complicated to compare. There is a chart comparing various subscription options in our full best satellite messenger review. We update that chart regularly, but details likely change even more frequently.


In your shopping, you will discover that devices sometimes come with more features than mentioned above. Notably, since SOS response requires GPS data, the devices include GPS antennae. With the hardware already there, manufacturers have taken steps to add navigational features to some products. With battery power precious, smartphone navigation being super accurate, and simplicity paramount in emergencies, we encourage you to think very critically before you rely a great deal on the navigational features of your communication device. At GearLab we value multi-functionality. However, communication devices are somewhere we might draw the line. Our advice is to keep it simple. We don't count on navigating with our satellite communication devices and don't think you should either.