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We demystify the satellite messaging market by putting the latest products and services from Garmin, ACR Bivy Stick, Starlink, and T-Mobile through extensive real-world testing
Many of our recently tested satellite devices. Roughly left to right: Garmin Fenix 8, inReach Messenger, Somewear, BivyStick, inReach Mini 3 plus, GPSMAP 67i, SPOT Gen 4, Zoleo, inReach Mini 2, inReach Messenger Plus, OceanSignal PLB1, Motorola, SPOT X
Credit: Jediah Porter
By Jediah Porter ⋅ Review Editor ⋅ Updated May 11, 2026
Whether you are venturing deep into the backcountry or simply exploring local trails with spotty cell service, a reliable satellite messenger is an essential lifeline. The best devices provide not only foolproof SOS capabilities in an emergency, but also peace of mind that comes with easily checking in back home.
The best stand-alone messenger is the Garmin inReach Messenger Plus. It has nearly flawless emergency and non-emergency messaging capabilities, allowing you to send photos and short voice memos. If you want to save $200 and don't need to send photos, the Garmin inReach Messenger is the better value.
That said, the T-Mobile T-Satellite service allows you to seamlessly message your contacts, use nearly 30 different apps, and costs only $10 a month. No extra hardware is required, which both saves you money and makes you totally dependent on your phone's battery life.
We took 14 satellite communicators out of cell service range and assessed their emergency and non-emergency functions, signal coverage, and ease of use. We used them for hundreds of hours and then compared the subscription plans to find the best overall performance and best value.
Editor's Note. On May 11, 2026, we added the Garmin GPSMAP 67i, inReach Mini 3 Plus, Fenix 8 Pro, and one from T-Mobile T-Satellite.
Not the absolute smallest on the market (but close enough)
Expensive
Tiny screen and limited on-device interface
The Garmin inReach Messenger Plus is the premier choice for reliable wilderness communication, combining Garmin's proven SOS protocols with the industry-leading Iridium satellite network. While two-way texting and SOS alerts are the baseline for any modern messenger, the Plus goes further by integrating seamless cellular-to-Wi-Fi switching and an intuitive smartphone app. Most importantly, it pushes the boundaries of standalone gear by enabling the transmission of photos and 30-second voice memos—critical features for sharing injury details or situational updates when every second counts. Compact, rugged, and feature-rich, it is the most capable lifeline available for the serious backcountry adventurer.
SPECIFICATIONS
2-way Messaging?
Yes
Pairs with Smartphone?
Yes
Measured Weight
4.1 oz
Battery Life
Up to 25 days
Satellite Network
Iridium
The Garmin inReach Messenger Plus is the only standalone device capable of transmitting photos and voice memos, but it carries a premium price for both the hardware and its specialized subscription plans. While this high-detail communication is a breakthrough for dedicated gear, it faces stiff competition from modern smartphones. As detailed below, new satellite-to-phone services offer similar—and often more advanced—functionality at a fraction of the cost, leveraging the powerful hardware you already carry. Overall, Messenger Plus remains the best option for robust backcountry communication and tracking.
Garmin inReach Messenger Pus in action. You could (and should) store the device itself inside a zippered, secure pocket in the top of your pack Credit: Jediah Porter
If you don't need to send photos and voice memos, the Garmin inReach Messenger saves you a hundred dollars over the Messenger Plus. Both devices have the same form factor and use the same satellite network and dispatch services. They share subscription rates and options. They both offer a rudimentary on-device interface and access to a much more useful smartphone app. Both offer long battery life and the option to charge small electronics from the internal inReach battery.
SPECIFICATIONS
2-way Messaging?
Yes
Pairs with Smartphone?
Yes
Measured Weight
4.0 oz
Battery Life
Up to 28 days
Satellite Network
Iridium
The inReach Messenger holds a battery advantage over the Messenger Plus during continuous operation. While both boast multi-week ratings—28 days and 25 days, respectively—the Messenger Plus only hits that mark in “Low Power” mode, which limits message checks to once per hour. In contrast, the standard Messenger maintains its 28-day lifespan while monitoring for messages continuously. If you run the Plus in “Performance” mode for constant monitoring, battery life drops to roughly 5 days. Ultimately, if you prioritize being alerted to incoming messages instantly without frequent recharging, the Messenger is the more efficient tool.
Garmin's refined inReach Messenger is a legitimate upgrade from their other offerings. It isn't perfect, but advancements do seem to be plateauing after a heady few recent years. Credit: Jediah Porter
If you have a phone released in the last 5 years, chances are you can use one of the best, best-value satellite services: T-Mobile T-Satellite. During our 2,500 miles of testing through notorious dead zones, it performed flawlessly, instantly connecting to the network without requiring us to stop, open a specific app, or physically point the device at the sky. It works incredibly well even while mounted on a car dashboard or bike handlebar, effortlessly sending texts and push notifications in areas with zero cell service. Because it eliminates the learning curve and runs in the background of your daily apps, it is the most user-friendly satellite messaging experience we have ever evaluated.
SPECIFICATIONS
2-way Messaging?
Yes
Pairs with Smartphone?
Yes
Measured Weight
0.0 oz
Battery Life
Depends on phone use
Satellite Network
Starlink
Despite its exceptional connectivity, T-Satellite's major vulnerability is its complete reliance on your smartphone. Unlike dedicated satellite messengers like the Garmin inReach series, it lacks a protected, physical SOS button and an independent battery source. If your phone battery dies during a multi-day trip—a highly likely scenario given the increased power drain of satellite communication—your only lifeline is instantly severed. Before relying on this service, carefully monitor your battery status and bring a portable power bank and/or a portable solar panel. Furthermore, while it supports some media, sending photos or videos results in long delays and severe battery drain. For high-risk, rugged adventures where guaranteed extraction is critical, relying solely on a fragile smartphone screen for emergency communication is a significant compromise.
Battery and interface are shared with other functions
The Garmin Fenix 8 Pro is incredibly compact and versatile. Its satellite connectivity is secondary to the GPS sports smartwatch's primary functionality. If you want satellite connectivity for short periods out of cell signal on long runs or bike rides, this is the product for you. If you want a smartwatch that frees you from your smartphone while still offering outdoor functionality, this is the product for you. It is also great as a backup to primary satellite communications in a group.
SPECIFICATIONS
2-way Messaging?
Yes
Pairs with Smartphone?
Yes
Measured Weight
2.8 oz
Battery Life
Up to 15 days
Satellite Network
Skylo
The Skylo satellite network used by the Fenix 8 Pro has limited coverage and is slower than other options. Furthermore, the Fenix 8 Pro needs a small antenna. This further slows and limits the Skylo connection. You have to aim the watch — in our testing, for up to 5 minutes and rarely less than 20 seconds — to send or receive a satellite message. Terrain, structures, and vegetation compromise all satellite connections; this effect is at least a little exaggerated on the Fenix. Finally, choose your satellite device wisely: do you want it integrated into a device that does other things for you, or do you want a standalone product for that important function? There are pros and cons to either side.
Incredible internet speeds for voice, video, and sharing large files
A relatively inexpensive monthly plan
CONS
Heavy and bulky relative to other satellite messengers
Requires an extra battery and power source for off-grid use
If your backcountry activity allows the weight and bulk of the Starlink Mini, it offers the ultimate in off-grid connectivity. It works effectively in nearly every part of the world, delivering exceptional internet speeds. The Starlink Roam Plan costs $50 per month for 50GB of data or $165 per month for unlimited use. Compared to the cost of unlimited messaging on most other services, this is a great deal.
SPECIFICATIONS
2-way Messaging?
Yes
Pairs with Smartphone?
Yes
Measured Weight
38.9 oz
Battery Life
Depends on size of external battery
Satellite Network
Starlink
The major downside of Starlink Mini is its weight and bulk compared to pocket messengers. While the panel weighs less than three pounds, it is bulky. More importantly, please carry an extra battery to power it. The smallest battery we would recommend is the Jackery Explorer 300, which weighs seven pounds. That will only give you about 10-15 hours of Starlink use unless you also have a solar panel. We would recommend at least a 100-watt panel, such as the Allpowers SPo12 100W Panel, which adds another 6 pounds. That entire setup now weighs approximately 17 pounds, which is way too much for a day adventure. While you could assemble a lighter-weight setup, you would have a lot less power. The lightest battery and panel setup would be a 100Wh battery and 40W solar panel, which still weighs about 7-8 pounds and would not be of much use when not exposed to direct sunlight, such as at night or in cloudy weather. Additionally, we don't recommend leaving the panel exposed while driving. Therefore, it does not offer reliable tracking, which is a key benefit of other trackers. In an emergency, it will take 5-20 minutes to get Starlink up and running if you have a clear view of the sky.
The Starlink Mini is ideal for camping or keeping in your car when you need high-speed internet and full functionality for your phone and laptop. Credit: Bryan Liscinsky
For a high-performance, sub-6-pound backcountry setup, pairing the Starlink Mini with the FlexSolar 60W panel and Anker 737 Power Bank creates an incredibly capable off-grid hub. This combination allows you to maintain high-speed internet while staying light enough for human-powered travel. Credit: Chris McNamara
The Starlink mini comes with a pole adapter to improve the signal in areas with tall trees. Credit: Chris McNamara
With only one battery and one 60 W panel, the Starlink mini weighs under 6 pounds. Credit: Chris McNamara
The Starlink Mini typically consumes between 25 and 35 watts during active use. Recent firmware updates and field tests have shown that the device is increasingly efficient, with steady-state power draw often settling at around 20 watts under optimal conditions. Credit: Chris McNamara
The Starlink Mini on the right is a fraction of the size and weight of the Starlink Gen two on the left. Credit: Chris McNamara
If custom messaging is not important to you and you're only looking for an emergency signaling device, the Ocean Signal rescueME PLB1 is your best option. It is expensive upfront, but there are no annual fees or subscription plans required. It broadcasts a distress signal through two radio channels, 406 MHz and 121.5 MHz. They are sent to a monitored satellite network and a local aircraft distress frequency. This powerful transmission is sent on the military's reliable COSPAS-SARSAT network.
SPECIFICATIONS
2-way Messaging?
No
Pairs with Smartphone?
No
Measured Weight
4.0 oz
Battery Life
Up to 1 day
Satellite Network
COSPAS/SARSAT
Unfortunately, this personal locator beacon does not confirm that anyone has received your distress signal. The PLB1 is an excellent option for pure, personal locator beacon SOS functions and offers a solid value. Still, the two-way messaging of many other options makes them more useful products overall. If you want more messaging functionality, check out the SPOT X, which has a built-in keyboard.
In the event of an emergency, simply deploy the rescueME PLB1's stow-away antenna and push the “SOS” button. Credit: Jediah Porter
Product Comparison Table
In all types of wilderness travel, effective communication is key. The products we review here all have their purpose, but some are definitely better suited for you than others. Shop carefully. Credit: Jediah Porter
How We Tested
To evaluate these tools, we purchased and activated the leading beacons and messengers on the market, subjecting them to hundreds of hours of testing across diverse latitudes, terrains, and climates. This rigorous field testing is backed by decades of professional experience in wilderness communications, ensuring our findings are as reliable as the devices we review.
We independently verify specs whenever it is practical to do so. Credit: Jediah Porter
We augmented field tests with consultation and lab tests. We prioritized real-world performance in the three areas that matter most: message reliability, signal coverage, and intuitive ease of use. Our findings are grounded in rigorous field testing and informed by direct consultation with SAR experts and satellite engineers. If you need a definitive resource to find your ideal lifeline, you've come to the right place.
Mountain guide Jediah Porter heads up our personal locator beacon review. Aside from testing gear, Jed's primary work is mountain guiding, including rock, ice, alpine, and ski mountaineering trips. Jed guides full-time all around the world. In each of the past few years, he has racked up over 500,000 vertical feet of human-powered ascent. In 2020, he ascended 800,000 vertical feet of human-powered mountain terrain, mainly while backcountry skiing. Aside from climbing and skiing, you can find him dabbling in mountain biking, canoeing, hunting, fishing, trail running, and other adventure travel. His latest adventure is in parenting; he and his toddler daughter have logged dozens of nights deep in the backcountry through each of her first four years. He almost always brings a satellite messenger or a personal locator beacon on his adventures, something his whole family appreciates. Jed brings professionalism, competence, and experience to test these important safety devices. Before taking over this category, he consulted for one of the major satellite communication networks and hardware providers for a few years.
Chris McNamara is GearLab's co-founder and has been using satellite messengers for the last decade. These days, his testing is mostly focused on answering the question: “If I am on a two-hour hike or bike in spotty cell service, which is the best option for letting my family know if I will be home on time?” Chris also has three decades of expedition experience and has used these devices in remote locations, from Baffin Island to the Australian Outback.
Composing a message on the device itself is a slow, laborious, one-letter-at-a-time procedure. But, it can be done and that is more than can be said of the inReach competitors. Credit: Jediah Porter
These guys are staying in touch with an inReach in their pack connected to their phone. The phone provides interface clarity that the device doesn't need to integrate. Essentially, your ubiquitous smartphone serves as the “screen” for the smaller device. Credit: Jediah Porter
The SPOT X ready to search for a signal. Credit: Jediah Porter
Analysis and Test Results
It has become increasingly common for wilderness travelers to carry and use satellite communications. While you may choose to head off-grid specifically to escape daily distractions, your loved ones likely hope you carry a reliable way to reach help.
What we test here is described elsewhere as “PLBs,” "Satellite Messengers," and “Satellite SOS.” PLB stands for “Personal Locator Beacon.” This term is largely confined to dedicated devices that send only emergency location information, such as the OceanSignal PLB1 and the ACR ResQLink. Any devices that send (and maybe receive) non-emergency messages are called Satellite Messengers. “Satellite SOS” is a function or mode on dedicated devices, or increasingly, built into other personal electronics, such as the newest iPhones.
Worse Value
Better Value
What's the Best Value?
Note that the initial purchase price is only part of your decision. Some devices may require a significantly higher upfront cost, but when you factor in activation and subscription costs, they are closer to, or even cheaper over the long haul.
For many users, the best value lies in the smartphone they already own. The iPhone pioneered free satellite messaging for non-emergencies, and many Android devices have followed suit. However, be aware that these phone-based services often rely on less robust satellite networks; unlike dedicated messengers, they frequently require you to stop, hold the phone steady, and manually track a satellite for several minutes to successfully transmit.
T-Mobile T-Satellite offers the best value for robust, off-grid connectivity. Messaging is nearly instantaneous, and the service now supports nearly 30 optimized apps, something no Garmin comes close to. Most users find it most cost-effective to keep their current provider and simply toggle the $10 monthly satellite plan on and off as needed for their adventures. In addition, you can buy a Revvl Phone for under $130 and add the $ 10-a-month service to it.
The best value for SOS/Emergency use is a device on the public-sector/governmental COSPAS-SARSAT network. The ACR devices are two examples. The rescueME PLB1 deserves recognition for its compact size and access to the proven and free international satellite SAR network.
October 2025 costs to own each messenger. Credit: GearLab
Finally, the best value for full internet connectivity, and really the only option we recommend, is the Starlink Mini. No other satellite service is close to offering the performance per dollar.
SOS/Emergency Messaging
For many adventurers, the SOS button is the only reason to carry a communication device. Search and Rescue (SAR) experts agree that in an emergency, they need to know two things immediately: where you are and how bad it is.
While older beacons relied on slow satellite triangulation, modern devices transmit your exact GPS coordinates the moment you press the button. Because a basic SOS beacon doesn't allow you to type out the details of your injury, activating it sends a universal, unmistakable message to dispatchers: “This is a life-or-limb emergency—get here as fast as possible.”
The SOS button on the SPOT Gen4. It is covered with the orange flap to avoid accidental deployment. Don't let an inadvertent SOS message get out: it's dramatic, to put it mildly. Credit: Jediah Porter
IMPORTANT: How Long Do Rescues Take?
The time from SOS activation to local SAR notification typically ranges from minutes to a few hours. However, the actual arrival of rescuers can take anywhere from hours to weeks, depending on terrain, weather, and available local resources. While all satellite and cellular systems provide roughly equal transmission speeds, the on-the-ground response is entirely dictated by local conditions and politics. Before heading out, always research the specific SAR capabilities of your destination, as they will have a far greater impact on your rescue than the device in your pocket.
Effective SOS messaging requires several factors to align: a functional device, an active registration, a clear view of the sky, and the mobility to trigger the alert. Never take these for granted. Our testing in the dense forests of the Northeast demonstrated that even in “civilized” wilderness, satellite signals can be blocked for days by heavy canopy.
A wilderness emergency is no place to begin thinking about emergencies. This knee injury eventually required ACL reconstruction surgery. Leaving the field was a smooth process, thanks to careful advance planning and good communications. Credit: Jediah Porter
Once you trigger an SOS, your device transmits a signal to one of four satellite networks. From there, the alert is received by one of six professional terrestrial dispatch centers that monitor all the devices we've tested.
Emergency response summoned from your satellite device is a function of the device and its service, plus a significant amount of variability in local resources. In fact, local SAR resources impact the outcome way more than the technology employed to summon that help. Credit: Jediah Porter
SOS messaging says, “I am here and in dire need of assistance.” This is all that SAR needs to know in the worst of emergencies. Of course, being able to relate more nuanced information and answer questions from SAR responders is of great value. Satellite communicators or personal locator beacons that allow two-way, customized communication improve emergency response.
Both SPOT devices, all Garmin devices, ZOLEO, and the Bivy Stick use private networks and emergency dispatch systems. Aside from coverage differences, elaborated below, they work the same for SOS messaging. Of these, only the SPOT Gen4 doesn't allow two-way messaging in any context. With the rest of the private sector devices and services, you can text the team to coordinate your emergency response.
In summary, the Garmin devices, ZOLEO, Global Hotspot, Bivy Stick, and SPOT X are the best for emergency messaging because they enable sending and receiving more nuanced information in an emergency. Additionally, the iPhone features several key Emergency SOS options that can automatically activate in the event of a crash or fall. However, you often need to configure these features in advance, and connecting to satellites typically requires holding your phone up and pointing it directly at one.
It doesn't take long, especially in the big and open American West, to get beyond the reach of cell signal. Have the equipment and a plan for contacting emergency resources, even on remote drives. Not to mention, of course, deeper into the wilderness. Credit: Jediah Porter
For “send help now” signaling and nothing more, the Ocean Signal rescueME, ResQLink View, and SPOT Gen4 are nearly indistinguishable and have long proven reliable. Apple's iPhone Emergency Satellite SOS functionality, as long as you are within the coverage area (currently the USA and Canada, with expansion theoretically ongoing), works similarly to two-way devices by allowing you to share more nuanced information about your emergency.
Emergency response via your T-Mobile T-Satellite service and device could vary. On T-Mobile iPhones, for now, emergency services beyond cell signal are handled by their Globalstar Emergency Satellite SOS app and dispatch service. On Android devices, emergency services via satellite are initiated like a standard 911 text message through the device's text app.
There are two major types of emergency messaging networks used by devices in our review.
Public — The COSPAS-SARSAT satellite network is a product of international government cooperation. Tax dollars fund it, and it is available for free use. It has provided satellite SAR support for more than 30 years. This network covers the entire planet and, with rare exceptions, is for emergency use only.
Private — These are for-profit services and partnerships operated by corporations or corporations. One example is Globalstar, the network that supports SPOT devices and the iPhone service. It currently does not cover the entire world. Be sure to research the Globalstar and SPOT coverage map to make sure it will work where you wish to adventure. Another example is Iridium, which supports the Garmin inReach, ZOLEO, and Bivy Stick. It covers the entire planet, and its track record over the past decade or so has been less imperfect than that of Globalstar's. The Iridium-supported devices we tested worked more reliably than the Globalstar-supported devices. Iridium and Globalstar-enabled services partner with an external monitoring and dispatch service.
From hitting SOS to response, each device type takes a slightly different path. (Note: All of the above applies to most areas we're familiar with. Your travel and rescue insurance may change the flow, as might the response in certain international regions.) Credit: Aaron Rice
Should You Navigate With Your Satellite Communicator?
The devices we test here are meant, first and foremost, to communicate with the outside world. In an emergency, the most critical information you can send with an SOS message is your exact location. Most of the devices we tested feature a built-in GPS antenna that provides location information, usually automatically. Once the hardware is in place, it is straightforward for manufacturers to add software that leverages GPS data for routine navigation.
Some of the devices we review have navigation features. However, these navigation features are often afterthoughts and drain the battery of a potentially vital piece of communication equipment.
Modern smartphone apps work so much better for navigation than your satellite communicator. We strongly recommend using a smartphone as your primary navigation mode. Because of that, we downplay (basically ignore) the navigational attributes of the satellite communicators we have assessed. If you plan to use your wilderness communication device for navigation, your only reasonable option, given its extended battery life, is the Garmin GPSMAP 67i.
The tiny screen of the Garmin Fenix 8 Pro is actually pretty good for the most basic of wilderness navigation. Again, this will draw power from your communication device.
If you navigate with your satellite device (or any device), please note that some terminology matters. Many people, ourselves included, inaccurately use “GPS” as a synonym for “GNSS.” GNSS is the proper, generic abbreviation for Global Navigation Satellite System. “GPS,” for “Global Positioning System,” is just one currently available GNSS. Devices are increasingly using different GNSSs. More GNSS options in a single device increase the resolution of location data. That increased resolution is more important for urban and highway navigation than for outdoor recreation.
The Zoleo satellite device on a Teton ski tour. Zoleo has tracking functionality in their service. Certain types of users in certain situations will appreciate this. Credit: Jediah Porter
Non-Emergency Messaging
Regarding non-emergency messaging, various options are available on these devices. Some have features that allow you to text and share your location, giving you the feel of using a smartphone. Others have a more straightforward approach, allowing you to send a quick message saying you're okay and where you are. Then, some have no non-emergency messaging options at all. Different devices offer different levels of performance and features. Additionally, some devices come equipped with location-tracking capabilities that can automatically share your location and status updates at regular intervals. Finally, one product on the market allows for the transmission of photo and voice messages.
Original inReach Mini on left, inReach Mini 2 on right. They are basically identical, from the outside. The second version has everything we loved about the original, and more. Credit: Jediah Porter
inReach Mini 2 on the left, Mini 3 Plus on the right. The Mini 3 is a little bit bigger and heavier, overall. Credit: Jediah Porter
There are five major types of non-emergency messaging:
1) Two-way texting with or without location data attached. This is, of course, the most useful.
2) Manual “OK” messages are transmitted, usually with location data attached.
3) Automated tracking. Automated tracking is a function in which the device will send location information to a front-country correspondent at predetermined time intervals, signal allowing.
4) The Garmin inReach Messenger Plus allows for sending and receiving photos and short voice memos.
In addition to all the other types of messaging. Various types of messaging can be sent to web interfaces, apps, text messages, and email addresses.
5) Starlink-enabled devices (whether that of the Starlink Mini or T-Satellite allow the use of most of your preferred messaging platforms. Starlink Mini allows all kinds of web connectivity.
The Garmin GPSMAP 67i provides all the basic forms of non-emergency communication. As does the inReach Mini 3 Plus and Messenger. Similarly, the SPOT X, Bivy Stick, Garmin Fenix 8, and ZOLEO offer all the above forms of non-emergency communication. The SPOT Gen4 has fewer options for non-emergency communications. It features pre-programmed “OK” message functionality with location data attached, as well as various tracking mode configurations.
Understand satellite coverage limitations before relying 100% on your fancy new device. Steep terrain is often problematic for all kinds of satellite communication. Credit: Jediah Porter
COSPAS-SARSAT personal locator beacons offer little in the way of non-emergency communication. The ACR ResQLink View and Ocean Signal rescueME PLB1 provide no explicit non-emergency messaging. That said, through an inexpensive subscription to “406Link,” you can replicate an informal “off-label” non-emergency message protocol. This service leverages a device “test” procedure to send notifications to friends and family, sometimes with location data attached. These “test” messages imply, “I am here, and my device works.” The test message could imply whatever more you and your informal emergency response network determine in advance.
The award winning inReach Messenger device and associated Garmin Messenger app. In use. Credit: Jediah Porter
This is nuanced. ACR once suspended the operation of its 406Link program for years, and its service description explicitly states that it “is not a 'check-in' or 'I'm ok' service.” However, in the same description, ACR implies that it might be used as described above. It is currently operational and, with a full understanding of all the parties involved, could provide bare-bones non-emergency messaging. Please do further research on its limitations and functionality.
Apple's Satellite SOS service on all the iPhone 14 models was, not long ago, a ground-breaking advancement in wilderness comms. It still works, but other options improve on the limitations. Credit: Jediah Porter
Apple's iPhone (Model 14 and newer) includes basic two-way texting, location sharing, and several emergency services (that often require configuring in advance). We love that iPhone messages come from your phone number: you aren't assigned a random new number, and you don't have to download a separate app. You also don't have to activate or deactivate a subscription. It just always works as long as you have the right phone and a clear view of the sky.
You might picture typical backpacking adventures when you think of a satellite messenger. But remote travel of any kind proves their utility. On a service farming trip in rural Puerto Rico in January 2019, we used satellite communications to coordinate logistics. Credit: Jediah Porter
Among the products and services offering two-way messaging, some of the newest options enable their messaging apps to work seamlessly over both satellite and cellular/Wi-Fi networks. With the apps from ZOLEO, Garmin, and Apple, you can have one conversation that moves with you from satellite signal to cell and WiFi. (From Garmin, only the latest devices --Messenger, Messenger Plus, Mini 3 Plus, GPSMap 67i-- are compatible with the app that provides seamless messaging. Older devices use an older Garmin app that does not support seamless messaging. This is very nice for smooth communication on trips and for people who frequently go in and out of the wilderness. The SPOT and Bivy Stick apps do not allow sending and receiving messages over cell/WiFi. It might seem minor, but this seamless messaging can greatly smooth communications in certain settings — like international travel or thru-hiking. You're in and out of signal, but want to participate in one clean, uninterrupted text chain with someone. The ability to do this has raised the bar for what we expect from our satellite messenger apps; we now expect all of them to support seamless text chains. Those communicating from home would especially appreciate this; they don't want to jump between messaging apps or contact entries if they don't have to.
On a long thru-hike having seamless messaging from your satellite device app (maintain the same text thread with satellite, cell, and wifi connection) is a great boon to the efficiency and clarity of your communications. Zoleo was the first to offer this. Others have followed suit. Credit: Jediah Porter
Signal Coverage
Each of the five satellite communication networks has coverage limitations, and all satellite communications have inherent restrictions. Additionally, we found differences in the reliable transmission of sent messages, even when coverage seemed intact. Because all remote communications are fraught, communication reliability is highest when it is “two-way.” We know from experience with one-way devices that the field user can “send” messages that no one is receiving. When the communications are “two-way,” confirmation of receipt is a little clearer.
Satellite Coverage
Terrain, vegetation, structures, and electronic interference all compromise message transmissions. These terrestrial variables are important regardless of your communication network or carrier and can determine your communication reliability. Some places never have satellite coverage. Other places will have windows when the signal is in and out. Few places have universal, perfect satellite coverage.
For obvious reasons, we could not and did not test the coverage and effectiveness of SOS messaging. Each device has a test mode that does not activate the entire SOS system. Those of us who have not yet had a backcountry emergency have to trust the manufacturers and the experience of other less fortunate users. For these ratings, we rely on research and SAR consultation.
The ResQLink View and rescueME PLB1 use the same network and communication protocol. These can be tested, but the life of a built-in, non-rechargeable battery limits the number of tests. All these “COSPAS-SARSAT” devices confirm functionality with on-device lights. This is limited in its ability to comfort you, as it doesn't involve satellite confirmation. Some also provide rudimentary test procedures that confirm the signal's actual transmission, but this drains the battery and sometimes costs more. Decades of history and anecdotal evidence confirm the global coverage and effectiveness of the COSPAS-SARSAT system that these devices employ. Aside from institutional knowledge and the basic on-device testing we performed, we cannot test the signal coverage of these three emergency-only devices.
The flip side of those Insta-famous destinations and photos is the tougher communications they might entail. You won't see high level wilderness communication planning on the influencer's pages; that's why we're here. Credit: Jediah Porter
The other options are easier to test for range and coverage using their non-emergency communication options. Our goal was to verify manufacturer claims. We found that sending non-emergency messages from each works as intended. The GlobalStar satellite network used by SPOT brand devices and the iPhone covers major terrestrial wilderness destinations for American adventurers. Within the limitations of the GlobalStar network, Apple service is limited even more than that of SPOT devices. The inReach, Bivy, and ZOLEO products use the same Iridium satellite network with global coverage. Within the inherent limitations of all satellite communications, these Iridium networked products work everywhere we've tested them, from California beaches to NE forests to Alaskan glaciers to Patagonia cabins.
With the newest update, the SPOT X includes Bluetooth functionality and an associated app, increasing the overall utility of this model. Credit: Jediah Porter
They use a satellite service called Skylo. Skylo is an intermediary that contacts a host of satellite communications hardware providers. This is how we understand Skylo to work: Many private-sector communications satellites are orbiting in space. A bunch of them cover the whole world and are owned and run by Iridium. Another whole bunch covers the inhabited latitudes and continents and is owned and run by GlobalStar. Then there are a bunch of individual satellites and smaller satellite networks at various orbital altitudes that serve different purposes and industries. Skylo works with many of these “other” satellite businesses to connect terrestrial Garmin Fenix, Google, and Samsung devices with overhead satellites.
Dense foliage in the otherwise (ostensibly...) innocuous small wilderness forests of the US East interfere significantly with satellite connectivity. In testing, we have found forests dense enough to entirely block all satellite signal. Credit: Jediah Porter
One of your Skylo messages might go through a low earth orbit satellite owned by company x. In contrast, the next might go through a geo-stationary, higher satellite owned by company Z. Skylo works all that out on the back end. Theoretically, this allows comprehensive coverage. In practice, Skylo provides a coverage map on its website that suggests coverage over all of North America and Europe. We have yet to test Skylo in enough places and contexts to thoroughly compare the satellite networks we know better. The “big four” satellite networks are proven and established, and we have deep institutional knowledge of their coverage and limitations. Skylo is newer. In our decade of testing, we watched one satellite communication “innovation” come and go. Any of these businesses and technologies can come and go, but we have more faith in those that have proven their durability over decades.
We also found subtle differences in message integrity. In a series of head-to-head tests, the Iridium networked devices are faster and more reliable than the GlobalStar devices, even with equal overhead coverage. Different devices, even from different brands, on the same network had statistically equal signal speed and integrity. Again, we found no difference in messages sent to or received from devices on the same satellite network.
Getting a good “fix” on a satellite with your iPhone is challenging. More so than with a dedicated device. Credit: Jediah Porter
As noted above, satellite connectivity is mainly a function of terrain realities and the chosen satellite network. We also have to discuss the ramifications of antenna size. Dedicated devices (like most of what we review here) have relatively large antennae. To include a satellite antenna in a smartphone or smartwatch is to shoehorn it among a great deal of other hardware. The satellite antenna in the iPhone is quite small compared to the other options we reviewed. That of the Fenix 8 Pro is even smaller. To optimize the connectivity of that small antenna, these satellite antennas must be aimed very closely. Other devices do not require this in the same way. The iPhone and Fenix are both equipped with on-screen prompts to help you aim them, but this does add complexity and time to your communications. Aiming and connecting to satellites is a big part of texting via satellite with your iPhone. It is a big enough hassle that satellite texting from an iPhone is best considered a rare and novel method of low-frequency, special-circumstance communication. You won't text back and forth as readily with your iPhone as you will with a dedicated device.
The “satellite antenna” of the T-Mobile T-Satellite service is actually the same antenna used for cellular connections. The Starlink satellites employed are close enough that the same antenna and usage patterns are appropriate. T-Satellite phones need not be pointed at the relevant satellites, unlike the iPhone Globalstar connection, which requires it. You can have an iPhone connected alternately to Apple's Globalstar service and/or, at any given moment, to the T-Satellite Starlink connection. These switch algorithms are not something you can force or access; the iPhone handles them automatically.
Garmin has changed their app landscape. With the latest Garmin satellite communication devices realize that you can update some software and change to the “messenger” app to get seamless texting across satellite, cellular, wifi. Credit: Jediah Porter
Finally, the Starlink Mini works basically everywhere in the world. The speeds have blown us away. You generally need a clear view of the sky. That said, even if you are in the forest, the Starlink will often still work; it will just cut in and out if you are making a video call or streaming a video.
The Starlink App makes it easy to find the optimal setup spot. Credit: Chris McNamara
Portability
Visiting the wilderness typically requires packing light. Therefore, the portability of your communications device(s) is important. Portability, for our purposes, is a function of weight and bulk.
The Garmin GPSMAP 67i is larger than most devices we tested, but it also does much more than others. We didn't mind the bulk until the inReach Mini came along. The Mini is less than half the size of the GPSMAP and does nearly as much. The inReach Mini 3 Plus is slightly larger than the original Mini and performs all the essential functions of the GPSMAP. The Bivy Stick is about the same size and weight as the Mini 3 Plus, and the inReach Messenger is slightly lighter.
The Bivy Stick with a compact multi tool for size comparison. This thing is really small, in league with the smallest options on the market. Credit: Jediah Porter
Size comparison of the SPOT X and inReach Mini. Clearly, the Mini is much more, well, miniature. Credit: Jediah Porter
The ResQLink View is heavier than the inReach Mini 3 Plus and Bivy Stick and does little more than the ultra-tiny OceanSignal PLB1. The Global Hotspot and ZOLEO are almost as portable as the Messenger Plus. The SPOT X is similar in size and weight to the Garmin GPSMAP 67i. The SPOT Gen4 is about the same size and weight as the Garmin Messenger or Bivy Stick. Notably, the SPOT Gen4 is slightly heavier than the Gen3, which is odd. We normally expect newer products, especially products with fewer functions, to be smaller than their predecessors. Garmin Messenger and Messenger Plus are the same size and shape.
You will likely have a smartphone with you on your outdoor adventures. Satellite connectivity on that ever-present smartphone could be considered the ultimate in "portability"; you already have it. iPhone models newer than the 14 have satellite connectivity built in, regardless of the carrier you use. Phones contracted with T-Mobile (regardless of the phone's make or model) can connect to Starlink satellites for texting. Some Samsung and Google phones (not tested here) connect to the same Skylo network as the Garmin Fenix 8 Pro.
There is a wide range of sizes, even in the most contemporary of choices. Three brand new satellite comm products, left to right: Garmin GPSMAP 67i, inReach Mini 3 Plus, Fenix 8 Pro. Credit: Jediah Porter
The bulkiest option in our test is the Starlink Mini. Although it weighs only a few pounds, it is significantly larger than the competition and requires a battery and a solar panel. That said, the Mini is roughly the size of a Frisbee compared to the larger Starlink options, which are more like pizza boxes and include a modem.
Wilderness adventures of all kinds (and adventurers, and loved ones of adventurers) benefit from at least basic satellite communications. Credit: Jediah Porter
Ease of Use
The combination of setup procedures and the in-the-field user interface largely determines the ease of use of this equipment. We evaluate both the on-device interface and the included networked app interface. While messaging functionality and coverage issues are important factors affecting overall ease of use, we will assess, compare, and rank them elsewhere in our review.
Smartphones like the iPhone are usually the easiest to use. You don't have to remember where you put the device (it's probably in your pocket). And you don't have to dedicate time before your adventure to making sure your subscription is current and at the level you need. No additional apps need to be downloaded or firmware updated.
The COSPAS-SARSAT devices — the ResQLink View and rescueME PLB1 — have identical setup procedures. You fill out an online form and await the arrival of your free registration sticker via mail. You can make changes down the road if needed through the online interface.
Setting up the SPOT, Bivy Stick, ZOLEO, and Garmin inReach devices is similar. All require you to select and activate a subscription plan. You often have to remember to turn your plan off or downgrade the service after your adventure.
Another size comparison of these two performers. Credit: Jediah Porter
The COSPAS-SARSAT personal locator beacons are super simple to use. For most people in most settings, the device will remain in your emergency kit for years with no changes, maintenance, or deployment required. The batteries are fixed and long-lasting. Few will use the device since the only features are for emergency use. All of these we tested have rudimentary instructions printed on the device. The instructions are accurate and effectively comprehensive.
With bluetooth connection to an associated app (here, Garmin GPSMAP 67i connected to Garmin Messenger app), the texting interface can be as simple as what you are accustomed to. Credit: Jediah Porter
For SOS use, the SPOT Gen4, SPOT X, inReach Mini 3 Plus, ZOLEO, Bivy Stick, and Garmin GPSMAP 67i are almost as simple as the COSPAS-SARSAT devices. Activate the SOS mode from either the device or from the app. You can send a pre-programmed “OK Message” from the app of many of the two-way messengers. With the SPOT Gen4, you must send the OK message from the device itself. With inReach, tPOT X, and ZOLEO, you can send an OK message from the app or directly from the device.
The touchscreen of the inReach Mini 3 Plus is great to have, but it is very slow and finicky to use. The keyboard on your phone, accessed through the Garmin Messenger app, is way way better still. Credit: Jediah Porter
Unintentional or undesired triggering of the SOS functionality is undesirable. As in any emergency reporting setting (crime, fire, etc), a “false alarm” has serious repercussions. We don't want to be part of a false request for a costly and dangerous emergency response in the wild. Any device/service with an SOS function is vulnerable to false alarms. Parents of toddlers who have called 911 from smartphones know what we are talking about… Given the severity of an SOS false alarm, we need to consider the technological and physical protection of the SOS trigger. Digital activations (from within messenger apps) require some “two-stage” activation. “Are you sure you want to call for help?” Physical buttons on most devices have a latched/secured cover for the SOS button.
The SOS button of the inReach Messenger Plus. Credit: Jediah Porter
Tracking speed records ("Fastest Known Time" or “FKTs” for short) is an emerging and important use of satellite communications. For these purposes you want simplicity, reliability, great web interfaces for the spectators, and really long battery life. The SPOT Gen4 could be a favorite in this realm, as could our top-scorers. Credit: Jediah Porter
Using the two-way, customizable messaging attribute of the Garmin Mini 3 Plus, Messenger, and GPSMAP, SPOT X, Bivy Stick, ZOLEO, or Global Hotspot requires further effort but is well worth it. Sending customized messages directly from the inReach devices is slow but works. None of the other two-way messengers can send or view messages without the app. On any of these devices, sending customized messages from the app is far more user-friendly than the onReach satellite messengers' on-device messaging. In this context, using your smartphone's familiar keyboard leverages the best attributes of the inReach, Bivy, and ZOLEO options. The SPOT X is usable with its app or entirely stand-alone. The device has a built-in, physical QWERTY keyboard. This makes it the easiest two-way texting device to use. The ZOLEO and Bivy Stick do not allow users to customize non-emergency texting without a smartphone. With the ZOLEO Bivy Stick, you can still send a basic “I'm ok” message if you lose cell phone service. Ensure your at-home team understands what this means before your travels. Sending messages from either inReach device is tedious but doable in a pinch.
Bluetooth connectivity and reliance on smartphone apps introduce a potential failure mode to your backcountry communication system. All three Garmin devices, Bivy Stick, SPOT X, and ZOLEO have Bluetooth and app connectivity to your phone. As you know from routine smartphone use, Bluetooth and apps inherently have potential issues. This baseline of potential unreliability is uniform across the board and is exacerbated by the realities of backcountry communication. Apps can be deleted from your phone, and Bluetooth connections can be “forgotten.” You cannot re-download a lost app without WiFi or cellular data in the wild. If the app relies on a web-confirmed account “login” and that “login” is interrupted, you can't reconnect in the wild. What have we found when comparing this “digital reliability” across app-enabled devices?
Texting on the physical keyboard of the SPOT X device. Credit: Jediah Porter
First, assuming the likelihood of app failure is nonzero, we will examine the consequences. The SPOT X is the best if you lose your app functionality. It has a large screen and a full QWERTY keyboard. The next best are all the Garmin devices. With all five Garmins we tested, you can perform all functions, albeit slowly and on smaller screens. Best is the touchscreen of the Garmin inReach Mini 3 Plus and Garmin Fenix 8 Pro. The Bivy Stick lets you trigger an SOS, send a check-in message, and activate tracking without the app. All texting requires a smartphone. ZOLEO allows SOS activation and sends a check-in message from the device.
Waiting for signal on the iPhone. It takes dozens of seconds, to minutes, to get a connection in the best of conditions. Credit: Jediah Porter
Next, what about the likelihood of an issue? First, we had no spontaneous app/device connection failures in our testing. All our testing was intentional “sabotage,” if you will, of the connection. The Bluetooth/app connection of the ZOLEO is robust. The only way we could get it to fail was to make a multi-step, in-signal process of “delete app account.” All Garmin products behave similarly. Bluetooth connection can be interrupted but regained in the wild. If you log out of either Garmin app, you need Wi-Fi or cellular to log back in. Though we haven't experienced it, we have read reports from other users of Garmin app login failures in the backcountry, resulting in reliance on on-device functionality alone. The relative likelihood of app/Bluetooth failure is hard to ascertain, as there are many more user hours on the Garmins than on the others. The bottom line is that the few failed inReach/app connection accounts aren't enough to draw any real conclusions from.
Wilderness travel is a high consequence environment. Make sure your equipment is up to speed and that you understand the use and limitations of your satellite communication device and service. Credit: Jediah Porter
Battery
Battery considerations for these satellite messengers are numerous. The best battery scores go to products with integrated batteries that are only used in the event of an SOS message trigger. This is the PLB1 and ACR devices.
Next in line are those with integrated batteries, intended only for use in two-way satellite communications. Devices that match this description are Garmin Messenger, Garmin Messenger Plus, Garmin inReach 3 Plus, Bivystick, Zoleo, and all the SPOT devices. There are subtle differences between those in this category, but they are more alike than they are different. The Garmin Messenger is best, with the “Plus” version not far behind. Both of these are special in terms of battery, because each can be used to “reverse charge” your other electronics if need be. Only on the longest of multi-day trips do you need to be ready to recharge one of these devices.
If you will spend a long time out in cold environments, your skills, habits, and accessories will dictate battery performance almost as much as the device will. Credit: Jediah Porter
After that, in terms of battery scoring, are the products in which satellite messaging is one of a few or more functions in the same device? iPhones and T-Satellite phones have satellite messaging, but you will also use them for lots of other things. In the backcountry, this might be navigation, entertainment, photo capture, journaling, etc. All these other functions drain the battery that you might need for satellite connectivity. Garmin GPSMAP 67i is the device you will choose for its GPS navigation features and satellite connectivity. Its battery is large and robust, but have a good plan for managing that battery if you will be both navigating and communicating with it. The battery of the Fenix 8 Pro is tiny and also powers navigation and activity tracking. For all of these multi-purpose devices, unless your outing is truly less than a few hours, we recommend carrying a backup battery (and a good plan for using and maintaining it) to ensure reliable satellite communications.
Small, standalone satellite devices are more similar than they are different, in terms of battery. That said, Garmin's “Messenger” line of products, on the left, have better battery performance than the inReach Mini line on the right. Credit: Jediah Porter
Finally, the most complex and demanding battery situation is that of the Starlink Mini. On its own, the Mini has no battery power; it relies entirely on external power. In the wild, you have to supply that power. And it is power hungry. We estimate that, for sustained and sustainable use in the wild, you will need a 17-pound kit of device, batteries, and solar panels to run the Starlink Mini.
Other Notable Satellite Messengers
Other Garmin inReach Mini Versions
We have now thoroughly tested three of the four “inReach Mini” devices that were ever made. And the fourth is one we can comment on via extrapolation. The original inReach Mini is now largely out of date. The existing models in use are likely experiencing battery decline. The connection technology is the same, but it charges via micro USB and cannot use the latest Garmin Messenger app. The inReach Mini 2 is the same size and shape as the original Mini, but charges with USB-C. If you have a Mini 2, it is still relevant and useful. The only upgrades in generation 3 are a touchscreen and a larger/heavier form. inReach Mini 3 Plus is the same as the generation 3 (larger than Mini 2, touchscreen), but also adds hardware to send and receive photo and audio messages. If you have an original Mini, upgrade to the Mini, Mini 3Plus, or Messenger Plus; it's worth it. If you have a Mini 2 and it's working for you, don't bother upgrading just now. If it is tired or you want a photo/audio function, consider getting a Mini 3 Plus or Messenger Plus. Touchscreen function alone isn't worth an upgrade from the Mini 2. We prefer the inReach Messenger Plus to any version of the inReach Mini. That said, many will default to the known “inReach Mini” form.
Skylo Service on Google and Samsung Phones
We haven't directly tested these products and services. We'll get to that as soon as we can. In the meantime, we can extrapolate a little bit. These use the same Skylo satellites as the Garmin Fenix 8, but with much larger antennae. Connection should be faster than we observed with the Fenix. All the caveats of using your smartphone for satellite connectivity apply: battery management is key, and you have no redundancy in communication.
Conclusion
The satellite communicator market is ever-evolving, and we look forward to continuing to bring you the latest backcountry communication devices.
