Notes

SOS Devices
SOS devices operate on satellite networks and transmit data, voice messages, and GPS coordinates to emergency response teams. They’re a lifesaver for hikers, mountaineers, hunters, workers in remote areas, and travelers in hazardous environments.

Unlike PLBs, these devices offer two-way communication. They also often come with tracking, navigation capabilities, social media posting, and weather reporting.
1. PLBs

Like EPIRBs (Emergency Position Indicator Radio Beacons), PLBs operate on the 406 MHz frequency and communicate with satellites to send a distress signal to rescuers. Unlike EPIRBs which are tied to specific boats, PLBs are registered to individual people. Once activated, a person’s GPS coordinates are encoded into the distress signal and relayed to rescuers via satellite. Some modern PLBs also have a 121.5 MHz homing signal that can be picked up by ground or aircraft detection devices. When you buy a PLB, you’ll be required to register it (free of charge) with vital personal data like your name, emergency contact phone numbers and medical conditions. These details help rescuers find you more quickly and easily.

When you press the SOS button on a PLB, it transmits your GPS location and beacon identification over the COSPAS-SARSAT network of global military satellites to a response center. From there, the response center looks up your emergency contacts and alerts the nearest rescue assets. The device will transmit a continuous SOS signal for at least 24 hours.

In contrast, a Satellite Messenger device uses private networks that have two-way messaging capability and link to your smartphone. This allows you to send your location, check in, and even a message that says “I’m in trouble” or just “OK”. All of the satellite-linked backcountry communication devices we carry (SPOT Gen4, all three Garmin InReach models, ZOLEO, Somewear Global Hotspot) offer this functionality.
2. 2-Way Satellite Messengers

The popularity of two-way satellite messenger devices like the SPOT Gen4, SPOT X, Garmin inReach Mini 2, ZOLEO and the Somewear Global Hotspot is on the rise. While these devices may not be as simple or cost-effective as a PLB, they can also serve as an emergency SOS device and offer much more versatility in terms of two-way communication capabilities, tracking features and coverage options.

These devices rely on commercial satellite networks to send both GPS coordinates and an emergency signal when triggered. The GEOS International Emergency Response Coordination Center near Houston receives all signals, then contacts local search and rescue agencies. They can even text you back as they coordinate a response to the SOS message, allowing you to share additional information such as your name, location and description of the emergency.

The biggest drawback of these devices is the need for a smartphone that must be paired to them via Bluetooth to access their full functionality. They're also limited to a single SOS activation, and there is no way to confirm that the SOS message was successfully transmitted. They do also have a tendency to take more time to connect to the satellites and transmit an alert than PLBs, especially in conditions such as thick dense foliage or extreme weather. This is one of the reasons that we recommend choosing a model that operates on the COSPAS-SARSAT network, such as the ACR ResQLink+ or the tiny rescueME PLB1.
3. GEOS

2-Way Satellite Messengers such as the Garmin inReach Mini and the new SPOT GEN 3 offer SOS features as well as navigation capabilities, tracking capabilities, and the ability to post your location to social media without a cell signal. They also allow for 2-way communication with rescuers if you activate the SOS feature or send a customized text message from the device.

These devices work on different networks but both have global coverage. GEOS operates the emergency response coordination for all SOS messages sent from the Tracertrak and Spot device (as well as other messaging devices such as Iridium). GEOS works with a network of official Search and Rescue Agencies around the globe to coordinate responses.

The GEOS International Emergency Response Coordination Center (IERCC) is the world’s most advanced system for responding to SOS messages from satellite emergency notification devices. Using a unique directory of SEND providers and their official SAR agencies, GEOS is the only SEND-based service that can guarantee you’ll be connected to a rescuer.

SOS signals from these types of devices require a valid subscription, current registration, and clear sky for signal transmission. They can be triggered by pressing a button on the device itself or through an app paired with it, such as on most phones. They’re designed to be simple to use and are a great addition to your survival gear. However, understanding all of the features offered by these devices will take a little more familiarity than PLBs and may need practice.
4. GEOS Mini

The GEOS Mini is a small, lightweight SOS device that’s less than half the weight of some PLBs. Its battery will remain dormant until activated, and it’s capable of generating a distress signal for up to 24 hours.

It also features two-way communication with GPS mapping, navigation, and tracking functionality. It can also act as an emergency beacon. Some models are able to automatically detect an SOS signal and can send a pre-programmed “OK” message from the device. Unlike most other satellite devices (except the Garmin InReach Mini 2 and Bivy Stick), GEOS does not require you to pair it with your phone for use.

During an SOS activation, your Mini will send your location and situation to a GEOS rescue coordinator who will work with local emergency services to coordinate the rescue. Man Down Panic Alarm The GEOS team is monitoring 24/7 and has coordinated rescues in over 160 countries. The service is included in the cost of a subscription.

The GEOS Mini is a great choice for backpackers who want the ability to connect to family and friends without worrying about losing mobile connectivity in the backcountry. It’s important to remember that the wilderness is dangerous, and no SOS device will completely eliminate risk. The ability to trigger a SOS can be lifesaving, but it’s important that you have a working satellite device, current registration, and a clear view of the sky in order to utilize it.
Website: https://mandowndevice.com/