Thinking of getting your own PLB?

Advice and things to watch out for

Yesterday is not ours to recover, but tomorrow is ours to win or lose. Lyndon B. Johnson

It’s worth spending a bit of time figuring out what features are important for a PLB unit. There are a great range of models on the market and nowadays are relatively affordable and last a long time. Read on for some more advice on where to purchase and features to look out for.

Purchase, hire and costs Find something that works for you

PLBs can be purchased from marine suppliers, aircraft re-fitters, bushwalking and camping supply stores. The cost varies (between $300 to $500 current as at Jan 2017) according to performance and specifications.

PLBs are subscription-free devices, so have no cost of ownership after the initial purchase.

Be aware that some overseas beacons are not compatible with the Australian system. The safest way to avoid this problem is to purchase your PLB from a reputable Australian retailer.
Australian Maritime Safety Authority (AMSA) provides a list of PLB distress beacon models that, if purchased in Australia, are known to meet Australian Standards AS/NZS 4280.1 and AS/NZS 4280.2, as well as a guide on choosing the right beacon, for details click here.

PLBs are available on loan at a nominal cost or for free from the National Parks and Wildlife Services (NPWS). For Sydneysiders, try the Blue Mountains Heritage Centre at Blackheath, and after hours at the Katoomba and Springwood Police Stations.

At the NPA, our regular leaders have long term loan units which they carry with them on all club trips. Our Sydney Branch office has an additional supply of units that members can borrow by contacting the activities coordinator ([email protected]).

GPS equipped Know why GPS equipped devices are so important

PLBs come in two basic types – those which provide an encoded (GPS) location and those which do not.

A GPS equipped PLB allows the beacon to acquire current location coordinates from an internal GPS receiver, sending an even more precise location of the beacon to the satellites, i.e., latitude and longitude data. This helps Search and Rescue Authorities (SAR) to reach the location even faster.

AMSA recommends beacons with Global Positioning System (GPS), which helps the rescue team to locate the distressed bushwalker. If your beacon is registered and activated correctly:

  • With a non-GPS beacon, your position could take anywhere between 90 minutes to 5 hours to locate with precision < 5 kilometres.
  • With a GPS beacon, you could be located within 20 minutes with precision < 120 metres.

Old vs New Distress Beacons Beware of old devices!

After 1 Feb 2010, old analogue EPIRBs and PLBs operating on 121.5 MHz are no longer licensed for use. You must carry a digital 406 MHz distress beacon.

The Old – 121.5MHz/243 MHz Analog Distress Beacon System
Analog transmission beacons have been replaced by the digital system are no longer supported. Analog devices should not be used any more, and must be disposed of immediately.
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The 121.5/243 MHz system was a simple analog system. Cospas-Sarsat ceased satellite detection and processing of 121.5/243 MHz beacons in 2009. These older beacons are now only detectable by ground-based receivers and aircraft. This means a beacon activated on this system requires a land receiver, aircraft or ship to be close enough to receive the signal; then the pilot/captain needs to be monitoring the channel, detect the signal, perform direction finding procedures and report it to authorities. This is patchy and random at best so is therefore totally unsuitable for an emergency system.

The major problem with this system was that it had an overwhelming number of PLB false alarms – AMSA indicates about 97% of activations were false alarms.
However, when an PLB is detected there is no way of knowing whether it is a genuine
emergency or not so they must assume it is genuine and send in resources to track it down.
This makes it a very inefficient and expensive system. This problem is one of the major
reasons the satellite tracking of 121.5MHz was ceased in February 2009.

All beacons on this old system should be disposed of appropriately.

The New – 406MHz Digital Distress Beacon System
The 406MHz system is digital and therefore allows more information to be sent when a beacon is activated.

Image courtesy of

Image courtesy of

Each 406 MHz distress beacon has a HexID or Unique Identification Number (UIN) programmed into it

The HexID is 15 characters long and is made up of hexadecimal numbers (0-9) and letters (A-F).

The HexID can be found on the label of all 406 MHz distress beacons.

This HexID must be provided when registering your PLB, and is the only code that links the distress beacon to the registered owner. This means you should register your 406MHz PLB with AMSA straight away!

The advantages of this identifying signal are:

  • Authorities know straight away whether the signal is received from a boat, aircraft or a bushwalker and can deploy resources appropriate to the incident more quickly.
  • Many false alarms can be eliminated easily as the received signal’s identification can be referenced to the registered owner of the beacon. The owner can then be contacted and the details of the incident established quickly.
  • It has a stronger signal strength so is more likely to be received from marginal areas
    such as gorges and under a tree canopy.

Other advantages of the new 406MHz system include:

  • The 406MHz system provides alerts far more quickly with alerts being received within minutes from the satellites in geo-stationary¹ orbit over the Equator.
  • The 406MHz beacons are located fixed by the polar orbiting² satellites to within 5km. These low earth orbit satellites also detect PLB’s in many areas that are hidden from geostationary satellites or hard to get an accurate reading from. Hence, using low earth orbit satellites means that rescuers are closer to the party that needs rescuing before they need to start direction finding.
  • The 406MHz digital beacons also have a secondary distress transmitter on 121.5MHz and is used for “homing” purposes. When the rescue services get close, this allows them to easily locate the beacon by using radio direction finding techniques.

Note 1. Geo-stationary Satellites: satellites that circles the Earth in a geosynchronous orbit, which means they orbit the equatorial plane of the Earth at a speed matching the Earth’s rotation. This allows them to hover continuously over one position on the surface.

Note 2. Polar-orbiting satellites: satellites that is constantly circling the Earth in an almost north-south orbit, passing close to both poles.

Cheatsheet for PLB purchase A quick summary of things to watch out for

If you’re thinking about purchasing a PLB for bushwalking, there are a few features to watch out for. Most modern PLBs are built to certain standards but it is worth double checking that the unit is appropriate for the activities you plan to do.

  1. GPS equipped
    Most modern PLBs are GPS equipped, but it’s important to double check as a more accurate transmission of your location will speed up rescue significantly.
  2. Transmission time minimum 24 hours once activated
    Once activated, most models of PLB will transmit continuously for a minimum of 24 hours. This is important if the rescue team cannot despatch a crew immediately, or weather conditions cause delays.
  3. Waterproof and self-buoyant or external flotation
    PLBs are generally watertight for a period of time but the duration depends on depth and temperature of the water, and the model of the PLB. Not all PLBs float – a problem if used in settings where there is deep water and potential to drop or lose the device (e.g. wet canyons)
  4. Appropriate battery life
    PLBs run on a battery that has a finite life (between 5 to 10 years) and should be replaced before the battery expires to ensure that the unit will still work in an emergency.
  5. Weight
    PLBs are getting increasingly lighter and smaller with every new model. Consider spending a little more to get a super lightweight, small model that can easily be carried.
  6. Appropriate temperature range
    Check the operating temperature range and make sure that it is appropriate for where you plan to use the device.

Example Image of a PLB, the SA2G model made by Kinetic Technology International. Battery life lasts 10 years, 24 hour transmission time minimum, GPS equipped and waterproof. See NPA purchased a number of these units to replace its fleet in 2016. So far, we have been impressed with this model for it’s size, battery life and costs.

Example Image of a PLB, the SA2G model made by Kinetic Technology International. Battery life lasts 10 years, 24 hour transmission time minimum, GPS equipped and waterproof. See NPA purchased a number of these units to replace its fleet in 2016. So far, we have been impressed with this model for it’s size, battery life and costs.

Registration How to register your PLB

AMSA now requires all PLBs to be registered.

A registered PLB allows the search and rescue authorities to phone your emergency contacts and look up important information to initiate a response as soon as possible. An unregistered beacon slows down this process, which might result in a delayed response.

You can register online (preferred method), or alternatively you can download, print and complete this form:

To register online you need to:

  1. Visit
  2. Select ‘register a beacon’.
  3. amsa 1

  4. Then follow the prompts and enter the information as required. You will need:
    1. The ‘Hex ID’, which is normally located on the side of the beacon and will contain 15 characters consisting of the letters A-F and numbers 0-9.
    2. Your name, and contact details.
    3. Three emergency contacts. These are the people that emergency services will contact to make sure that the PLB has not been accidentally set off, and can provide a bit more information. Make sure you choose people that are likely to have phone reception, usually respond quickly to phone calls, and know details of your trip. Also, choose people that keep a cool head in an emergency.
  5. You can also enter a bit of general information about the PLB. We recommend you enter a statement similar to this, but modify the details to suit your walking habits: “This PLB is used by {your name}. Walks are typically done in the [insert name] region. Walks involve on-track, off-track walking, overnight trips, and canyoning”.
  6. You can also enter specific trip intentions for individual trips. We recommend you do this for your activities out of mobile coverage, especially overnight trips, and trips with significant off-track sections.

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Advice on where to carry your PLB A quick summary of what to think through

Storing the PLB in your first aid means that it automatically comes with you when you packs your first aid kit, and is quick to find in an emergency. Before starting the trip, remind everyone in the group where the PLB is stored, and run through how the PLB is triggered in an emergency.

If travelling solo, make sure that the PLB is somewhere easy to reach, near the top of your pack. If you take your pack off to explore a side gully, collect water, or check out a campsite, carry the PLB on your person. Some PLBs have arm bands so you can attach the beacon to your body for easy access.