A rescue beacon is a compact device that can be carried in your pocket, pack or vehicle, which you can use to summon help via a satellite network when a life threatening situation arises and you are unable to call 911.
Why carry a beacon?
Time is a crucial factor in many rescues. There are many areas within a few miles of the I-90 and SR-2 corridors where cell phone coverage drops very quickly. If someone is injured, you may have to travel many miles to summon help, potentially leaving the injured party alone, and adding an hour or more delay for activation of a search and rescue mission. On missions to find lost subjects, we search for hours or sometimes days to find them. A beacon location enables our teams to more quickly transition from search to rescue mode.
What are the different types of rescue beacons and how do they work?
A 406 MHz Personal Locator Beacon (PLB) transmits to a government satellite network which, for the inland United States, routes the alert to the Air Force Rescue Coordination Center, which in turn alerts the relevant search and rescue jurisdiction. For King County, they are sent to the Washington state SAR coordinator, then King County Sheriff’s Office.
PLBs use the same frequencies (406 MHz) and protocols as EPIRBs on boats, and ELTs on private and commercial aircraft. PLBs do not require an annual subscription for their primary function: emergency activation.
A PLB requires two steps to activate the emergency beacon, typically by pressing two buttons at the same time, or moving aside a cover and pressing a button. Once the beacon is activated, several things happen. The PLB tries to establish its location using GPS satellites. It transmits a signal to the COSPAS-SARSAT satellite network, which includes both the unique identity of the beacon, and also the GPS location (about 100m resolution) if one has been established. It also begins to transmit a homing signal on 121.5 MHz.
The Rescue Coordination Center is able to access the information associated with the beacon identify at time of registration. Registration and updating information at www.beaconregistration.noaa.gov/ is required immediately after purchase and then every two years. NOAA will send you a registration sticker to affix to your PLB, and reminder emails when renewal is due. This service is free.
This registration information along with the best location available is then sent to the search and rescue authority for that beacon’s reported location. PLBs work worldwide, and the appropriate rescue coordination center for the area will route it to search and rescue authorities for the country or region you are in, though outside the US, they do not have access to the NOAA beacon registration information.
When the King County Sheriff’s Office receives a beacon activation alert, it is dispatched to the Search and Rescue deputy on call, who will alert the King County Search and Rescue ELT team.
We will dispatch resources to the area, and begin to use our ELT locators to track the 121.5 MHz signal the “final mile” to the beacon location and render appropriate assistance.
Some PLBs also support non-emergency text messaging and tracking subscriptions, though typically the number of transmissions possible per year is limited.
A Satellite Emergency Notification Device (SEND) transmits to a commercial satellite network and then to a commercial rescue coordination center which will in turn alert the relevant search and rescue jurisdiction. Some SENDs offer 2-way communication and can send and receive text messages.
Because they use commercial satellite networks and RCCs, the exact process varies by device or manufacturer. SEND devices do not have a 121.5 MHz homing beacon, so our ELT team is not activated – our teams will use the location reported by the rescue coordination center.
SENDs typically require you to pay an annual subscription for emergency coverage, and offer various packages that include emergency and optional non-emergency text communication and “bread crumb” tracking viewable by friends and family.
When should I activate my rescue beacon?
Unlike a cell phone call to 911 where the dispatcher or deputy can have a discussion with the reporting party and establish the exact situation and find out what type of assistance is needed, activation of a beacon typically does not provide us with much information about the nature of your emergency.
You should activate your beacon in a life threatening emergency, where you are injured and need medical assistance and cannot travel to safety, or when you are lost and think you cannot find your way back to safety. Obviously your supply of food and fresh water, availability of shelter from weather conditions, and medical condition should be factors in your decision to activate your beacon.
Will I be charged for activating it?
Under Washington state law, there is no charge for search and rescue services. As with a 911 call, if you are injured or lost, you should alert authorities to your situation promptly. Waiting to call us – especially when your situation is unlikely to improve – could reduce your chances of survival, and possibly increase the risk to our volunteers.
Beacons and the Ten Essentials
A beacon ensures that you can always summon help in emergency situations. If you travel outside of your cell phone coverage area, we recommend that you carry a beacon as part of the Ten Essentials.
Note to skiers: PLBs are different than avalanche beacons. When backcountry skiing, you should carry an avalanche beacon.
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