What is an emergency alerting device and when do you need one? What type is best suited to where you’re going and what you’ll be doing? And what should you consider before buying? We assessed 13 devices to see how they differ.
Emergency alerting devices are for anyone heading into the remote outdoors – such as trampers, mountaineers, hunters, kayakers and boaties.
Accidents happen. You or someone with you could suffer a major injury or medical incident, you could get trapped or lost, or your boat could start to sink. With an emergency alerting device, you can send a distress signal (sometimes referred to as an SOS) to search and rescue services.
While mobile phone coverage is limited, emergency alerting devices have near-global reach via satellites.
Types of emergency alerting devices
There are different emergency alerting devices for use on land and water.
• Emergency beacons, which include:
• EPIRBs (emergency position-indicating radio beacons) – for boats
• PLBs (personal locator beacons) – for land and near-to-shore water activities.
• SENDs (satellite emergency notification devices), which are also referred to as satellite messengers or satellite communicators.
Aircraft also have a beacon, called an ELT (emergency locator transmitter).
EPIRBs and PLBs have a single purpose: to send a one-way distress alert in an emergency. When you press the alert button, the signal goes to a network of international search and rescue satellites. It’s then transferred to your local Rescue Co-ordination Centre, which organises a search and rescue operation to find you. Distress transmissions include the beacon’s unique ID and real-time GPS position.
• They don’t require any set-up before they’ll work. But they must be registered, so the search and rescue teams know who they’re looking for and have your emergency contacts.
• They use the COSPAS-SARSAT global search and rescue satellite network, which has better coverage than the satellite networks SENDs use. Emergency beacons will get a signal in some places that SENDs won’t.
• There are no subscription fees to pay (which there are for SENDs).
• Emergency beacons transmit a ‘homing signal’ in addition to the distress alert. This helps local rescue teams narrow down the search once they’re nearby.
• Their batteries don’t need recharging. Emergency beacons have single-use batteries that have an expiry date. But since their use is reserved for sending a distress alert in an emergency, they last on standby for several years.
• Manufacturer warranty periods are long, ranging from five to eight years.
EPIRBs (emergency position-indicating radio beacons)
EPIRBs are the emergency beacons used on boats – certain types of vessels are legally required to have one. They must be registered and mounted to the vessel.
All can be manually removed from their mounting brackets and activated. Some (called ‘float-free’ EPIRBs) will automatically release and activate if a boat capsizes or starts to sink. They’re for large boats and commercial vessels.
EPIRB batteries have 48 hours’ run time, typically with 10 years’ shelf life. They cost around $500 to replace.
PLBs (personal locator beacons)
PLBs are the emergency beacons primarily used for land-based activities and near-to-shore water activities such as kayaking, paddleboarding and dinghy use. They must be registered to an individual.
They need to be manually activated and should be attached directly to an individual or in an accessible spot on their lifejacket or backpack strap.
PLB batteries have 24 hours’ run time with five to eight years’ shelf life. They cost around $300 to replace.
SENDs (satellite emergency notification devices)
SENDs – also referred to as satellite messengers or satellite communicators – are not emergency beacons. SENDs are rechargeable multifunction devices with messaging plus additional features such as tracking, navigation and weather reports.
They can be used to manually send a distress alert with GPS co-ordinates from the user’s location, but they differ from emergency beacons in several ways.
• SENDs won’t work until they’re set up. This typically includes charging and configuring the device, signing up with an account and subscription plan, and installing a phone app.
• SENDs use a commercial satellite network and coverage is not as good as the COSPAS-SARSAT network that emergency beacons use. SENDs might not get signal deep in the bush, in a canyon or in a crevasse.
• There are ongoing subscription fees to pay for use of the commercial satellite networks (Iridium or Globalstar). Terms and pricing vary between providers.
• SENDs don’t transmit a homing signal (which emergency beacons do). They have interactive messaging, allowing the user to provide additional information about their emergency or cancel the emergency alert if help is no longer required.
But the user must be capable of messaging to use this feature to aid search parties. By contrast, the homing signal on an emergency beacon works irrespective of the user’s condition – injured or otherwise.
• Their batteries need recharging. Use of a SEND’s various features runs down its battery. SENDs also require an app to operate some functions. Therefore, users need to carry a power bank for longer trips to keep both their SEND and their phone charged.
• Manufacturer warranty periods are short – one to two years.
What to consider before buying
Choose the right device for your activity and location (see ‘Types of emergency alerting devices’). For remote messaging and other non-urgent features, you’ll want a SEND. But it shouldn’t be relied on as your only emergency alerting device.
Wherever you’ll be going, take a PLB or EPIRB too. These are the best choice for getting help fast in an emergency.
• Make sure any PLB or EPIRB you buy is NZ-coded so it can be registered with New Zealand’s Rescue Co-ordination Centre, providing the fastest response to your distress signal.
• If you’re travelling overseas, check what devices are permitted. Some countries regulate or prohibit satellite devices such as PLBs and SENDs, and some regions have limited or no search and rescue services.
• Check any PLB or EPIRB has GPS – older models may not. Transmitting precise coordinates will make you much easier to find.
• Make sure the device you choose is logical and easy to use, and ideally has directions printed on the unit that are easy to read. Injuries and very cold, dark or wet conditions will make it more difficult. If you’re unconscious, someone else might need to activate the beacon for you.
• Check it has good protection from accidental activation. You don’t want search and rescue resources sent unnecessarily – it could delay someone else getting urgent help.
• For PLBs and SENDs, choose one that’s convenient and comfortable to wear with secure attachments. Consider weight and size, and whether it can be secured or will swing about. It’s no good inside your backpack if you’re dangling from your pack straps.
• Look for additional safety features such as strobe lights and reflective elements. Check whether the device will float and what its waterproof rating is.
• Think about how often you’ll need one. For infrequent use, it may be more cost-effective to hire instead of buying when you consider SEND subscription fees, or the cost of replacing a PLB’s or EPIRB’s battery when it expires. Take account of warranty periods too.
• The shelf life of PLB batteries varies, so compare models. And make sure the supplier of any PLB or EPIRB can tell you where you’d need to send it for battery replacement and how much it will cost.
• For SENDs, make sure you’re aware of the ongoing subscription costs of using the features you want and need.
Get the device ready before your trip
• Prepare your device: Register EPIRBs and PLBs (it’s a legal requirement) and keep your details up to date. A registration form is included with these devices. Set up your SEND well in advance and charge it fully. You won’t be able to use it until you have, and set-up can take time. If you’re not ready to buy, hire instead.
• Test the battery of any EPIRB or PLB: Follow the directions in the user manual. Some models require interpretation of a sequence of lights. If you’ve activated your EPIRB or PLB to send an emergency alert or by accident, you’ll need a new battery.
• Make sure everyone on the trip knows where the beacon is and how to use it: EPIRBs come with clear instructions about where they must be mounted. PLBs and SENDs should be attached to a person somewhere they’re easy to access and activate. Show all parties where the device is and practise the steps for sending an emergency alert (SOS).
This report is free thanks to funding from Maritime New Zealand Nō te rere moana Aotearoa and New Zealand Search and Rescue Rapu Whakarauora Aotearoa.