01/09/2026
𝐀 𝐃𝐢𝐬𝐭𝐫𝐞𝐬𝐬 𝐁𝐞𝐚𝐜𝐨𝐧 𝐥𝐢𝐤𝐞 𝐄𝐏𝐈𝐑𝐁, 𝐌𝐎𝐁 𝐨𝐫 𝐏𝐋𝐁 𝐢𝐬 𝐲𝐨𝐮𝐫 𝐒𝐞𝐚-𝐜𝐫𝐞𝐭 𝐰𝐞𝐚𝐩𝐨𝐧 𝐭𝐨 𝐜𝐚𝐥𝐥 𝐟𝐨𝐫 𝐡𝐞𝐥𝐩.
You’re Miles Offshore. Something Goes Wrong. Now What?
That’s not hypothetical for NSW boaters. It’s a real situation that happens every season. Marine Rescue will be here to help you but there is a lot you can do to make our response more effective. The EPIRB vs PLB question isn’t just a gear debate. It’s a safety decision that could affect how fast our rescue teams find you.
Mobile phones fail with distance, flat batteries, and spray. When voice contact is gone, a registered EPIRB or PLB can turn a mechanical failure into a survivable wait for help.
𝐌𝐚𝐤𝐞 𝐬𝐮𝐫𝐞 𝐲𝐨𝐮 𝐡𝐚𝐯𝐞 𝐚𝐥𝐬𝐨 𝐋𝐎𝐆𝐆𝐄𝐃 𝐎𝐍.
To Log On, call your local Marine Rescue NSW base. Marine Rescue Hawkesbury is on 9985 2100 or use VHF Channel 16 or use the free Marine Rescue NSW app. You can download the app at the App Store for Apple devices or Google Play for Androids. It's free and it could save your life. Read on to learn a bit more about Distress Beacons and MMSI (maritime mobile service identity)
EPIRBs and PLBs both transmit distress signals via satellite, MOBs are for more local situations. They all work differently, and they’re used in different situations. Getting this wrong isn’t just inconvenient. It can cost you time when time is the only thing that matters.
𝐄𝐏𝐈𝐑𝐁: 𝐁𝐮𝐢𝐥𝐭 𝐟𝐨𝐫 𝐭𝐡𝐞 𝐁𝐨𝐚𝐭, 𝐍𝐨𝐭 𝐉𝐮𝐬𝐭 𝐭𝐡𝐞 𝐏𝐞𝐫𝐬𝐨𝐧
An EPIRB (Emergency Position Indicating Radio Beacon) is designed to stay on the vessel. It is a last-resort distress tool, not a day-to-day chat device. Most models mount near the helm or in a bracket close to the cockpit. Float Free EPIRBs activate automatically when submerged to a depth of one to four metres underwater. Otherwise they require manual activation. Either way, it starts transmitting your location fast. Some EPIRBs such as the GME MT605G have an IR (infrared) strobe light for improved Search and Rescue Visibility.
In NSW all domestic commercial vessels and any vessel going more than 2NM offshore must have an EPIRB that is:
- Registered
- Compliant with the latest laws
For offshore fishing boats, sailing vessels, and anyone running more than 2 nautical miles out, an EPIRB is usually the right call. It has a longer battery life than a PLB, typically 48 hours of continuous transmission versus a PLB’s 24-hour life. That window matters when you’re dealing with rough seas, fog, or a nighttime emergency far from shore.
Registration is non-negotiable. Your beacon must be linked to your vessel for information, contact details, and emergency contacts in the official Australian Maritime Safety Authority - AMSA database. Without proper registration, our rescue teams are working with partial information. That slows everything down.
And yes, buoyancy is built in. Australian Emergency Position Indicating Radio Beacons (EPIRBs) are specifically designed to float. This feature ensures that the antenna remains above water, which is crucial for optimal signal transmission during emergencies. If your boat is going down fast, that matters. Unlike a PLB your EPIRB should be floated if your boat has gone down to ensure optimal transmission, of course you should keep it tethered to you or your life raft.
𝐏𝐋𝐁: 𝐏𝐞𝐫𝐬𝐨𝐧𝐚𝐥, 𝐏𝐨𝐫𝐭𝐚𝐛𝐥𝐞, 𝐚𝐧𝐝 𝐠𝐮𝐚𝐫𝐚𝐧𝐭𝐞𝐞𝐝 𝐭𝐨 𝐦𝐚𝐤𝐞 𝐲𝐨𝐮 𝐩𝐨𝐩𝐮𝐥𝐚𝐫 𝐰𝐡𝐞𝐧 𝐟𝐥𝐨𝐚𝐭𝐢𝐧𝐠 𝐨𝐟𝐟𝐬𝐡𝐨𝐫𝐞
A PLB (Personal Locator Beacon) goes with the person, not the boat. You clip it to your life jacket, your gear bag, or your belt. When something goes wrong, you generally deploy the antenna and activate it manually. Some lifejackets have the PLB integrated to activate automatically when the life jacket inflates. It sends your GPS coordinates to search and rescue within minutes.
PLBs are popular with kayakers, paddleboarders, solo anglers, and anyone spending time on smaller vessels. They’re also a solid backup option even if you already carry an EPIRB. If you go overboard and the boat drifts away, that EPIRB isn’t helping you directly anymore. Your PLB is. If you've ended up in the water, the comrade who is wearing a PLB is your new best friend. Our unit can only afford one PLB per boat crew so the member wearing it is guaranteed close company if we all go overboard (see below for how you could help us out with a donation so we can buy more PLBs).
Battery life on a PLB runs around 24 hours. Shorter than an EPIRB, but still long enough for our rescue teams to find you in most scenarios. Some PLBs also have a strobe light which is much brighter than the ones generally fitted to life jackets.
For boaters operating on inshore waters like our Hawkesbury River a PLB can be the best option. If you've fallen out or run aground you may no longer be in the vicinity of your EPIRB and anyone who knows our river can tell you how fast the current can move you along. To have a PLB transmitting your exact location every 30 seconds could make your rescue much quicker.
Registration works the same way, linked to you personally through the AMSA beacon registration system. If the beacon activates, our volunteers know exactly who they’re looking for. Keep that info updated. Phone numbers change. Boats change. Registration details should be included.
𝐍𝐨𝐭𝐞: PLBs are not considered a substitute for EPIRBs when adhering to State and Territory marine carriage regulations.
𝐀𝐈𝐒 𝐌𝐚𝐧 𝐎𝐯𝐞𝐫𝐛𝐨𝐚𝐫𝐝 (𝐌𝐎𝐁) 𝐝𝐞𝐯𝐢𝐜𝐞𝐬
Man Overboard devices use AIS to provide immediate notification to the parent or neighbouring vessels relating to a Man Overboard (MOB) incident and provide a means of location to determine the position of the MOB. MOB devices are NOT part of the COSPAS SARSAT dedicated emergency 406 frequency search and rescue network and therefore should not be referred to as Personal Location Beacons or PLBs. The issues in using one of the older 406 MHz PLBs in a MOB situation are the variable latency period from activation to rescue depending on location and that vessels in the vicinity, including the Mother vessel, aren’t alerted to an MOB incident until they are contacted by shore Search and Rescue authorities, which limits opportunity for local recovery and extends the time in the water.
An older 406 MHz PLB is not primarily designed as an aid to a local recovery, as its distress alerting is dependent on communication with the official SAR network whereas, a localised alert via an AIS MOB device greatly increases your chances of local identification and rescue should such support be readily available. Once activated the position of the AIS MOB device will be displayed as a GPS located target icon on vessels in the vicinity with AIS enabled plotter screens. A burst of messages repeat every 1 minute, with the cycle of messaging repeated many times to overcome wave action and to achieve line-of-sight to a nearby vessel. In a heavy sea with the AIS device close to the sea surface, wave swell can block the transmissions. This is overcome via information being repeated every 2 seconds (over 14 seconds), ensuring some transmissions will coincide with the person adrift being on a wave crest, allowing “line-of–site” path for message relay. The vessel will get a range and bearing to the exact location, which is updated, in real time to recover the drifting MOB.
An MOB can be activated manually or automatically when installed within an inflatable life jacket (automatic).
Best for: Boaters in coastal areas or participating in races where immediate local assistance is available.
Advantages:
- Quick alerts to nearby vessels.
- Ideal for crewed boats where rapid response is crucial.
Marine Rescue Broken Bay Marine Rescue Cottage Point Marine Rescue Brisbane Water and our own Marine Rescue Hawkesbury unit all have equipment on board which will alert us and help us quickly locate you if you activate an MOB device in our local waterways.
𝐏𝐥𝐞𝐚𝐬𝐞 𝐍𝐨𝐭𝐞: You can now purchase PLBs that transmit on AIS and 406MHz, that would be the best option.
𝐄𝐏𝐈𝐑𝐁 𝐯𝐬 𝐏𝐋𝐁: 𝐓𝐡𝐞 𝐑𝐞𝐚𝐥 𝐃𝐢𝐟𝐟𝐞𝐫𝐞𝐧𝐜𝐞𝐬 𝐒𝐢𝐝𝐞 𝐛𝐲 𝐒𝐢𝐝𝐞
Here’s where boaters get confused in the EPIRB vs PLB comparison. Both transmit the same frequency of 406 MHz, and both connect to the Cospas-Sarsat satellite network, a satellite-based distress-alert detection system. So, on paper, they look similar. But the details matter.
EPIRBs are larger and vessel mounted. They’re best for offshore boats where the vessel itself needs to be tracked. Buoyancy is a standard feature. Battery life hits 48 hours. Most Australian EPIRBs (Emergency Position Indicating Radio Beacons) do not automatically activate. Users must manually activate these devices in case of an emergency. This design choice ensures that the EPIRB is only used in genuine distress situations, preventing accidental activations.
Importance of Manual Activation
- Prevents False Alarms: Manual activation helps avoid unnecessary search and rescue operations.
- User Control: It allows the user to assess the situation before signalling for help.
Auto-activation is available on float free EPIRBs. It activates only when a vessel is submerged to a depth of one to four metres underwater. A float-free EPIRB can also be manually removed from its bracket and manually activated without it being submerged in water. Float-free EPIRBs are buoyant and float to the surface of the water with the aerial pointing vertically and transmitting a distress signal. Boats often roll upside down before they sink, so avoid mounting your float free EPIRB in areas that might trap the beacon as it floats free.
PLBs are compact and personal. They go wherever you go. They don’t float on their own in most cases, so they need to stay attached to you or your gear. Battery life is around 24 hours. Check out the Australian built GME MT610G for a floating PLB. Having a PLB with an inherently buoyant design is advantageous, if you drop it in the water it isn't nice to see such an expensive piece of kit go straight to the bottom.
For NSW boaters running offshore, an EPIRB on the boat and a PLB on your body is the strongest setup. It’s not either-or. It’s both when conditions demand it.
The activation process for both beacons is designed to be simple. That’s intentional. When things go sideways offshore, you’re not reading a manual. You’re reacting. Battery life becomes a real factor during multi-day trips or when weather delays a rescue window. A 48-hour EPIRB transmission window gives rescue crews more time to work with. That matters. And buoyancy isn’t just a technical spec. It’s the difference between a beacon still transmitting on the surface and one sitting on the ocean floor.
Don’t Skip Registration. Ever.
This is where far too many boat owners drop the ball. They buy the beacon, store it onboard, and never complete registration. Or they update their boat but forget to update the registration attached to the beacon.
Both the EPIRB and PLB require registration through Australian Maritime Safety Authority - AMSA. It’s free to register but not having your beacon registered in some cases can lead to a penalty fine. The official site is https://www.beacons.amsa.gov.au/Public/PreRegistration/Beacon. No payment is required. Registration only takes a few minutes. And it’s the step that connects your signal to your name, your boat, and someone who can call for help on your behalf. Don’t skip it.
𝐏𝐨𝐭𝐞𝐧𝐭𝐢𝐚𝐥 𝐏𝐞𝐧𝐚𝐥𝐭𝐢𝐞𝐬 𝐟𝐨𝐫 𝐮𝐧𝐫𝐞𝐠𝐢𝐬𝐭𝐞𝐫𝐞𝐝 𝐛𝐞𝐚𝐜𝐨𝐧
- Fines: AMSA may impose monetary fines for failing to register a distress beacon.
- Enforcement Actions: Additional enforcement measures may be taken against individuals or operators who do not comply with registration requirements.
𝐌𝐨𝐛𝐢𝐥𝐞/𝐬𝐚𝐭𝐞𝐥𝐥𝐢𝐭𝐞 𝐩𝐡𝐨𝐧𝐞 𝐨𝐫 𝐫𝐚𝐝𝐢𝐨
Two-way communications via a mobile/satellite phone or radio is the most effective means of communication when in a distress situation, with some of the reasons outlined below:
- Instant confirmation that the call has been received by emergency services;
- Ability to communicate position, nature of distress, required assistance;
- Emergency services can adequately scale response assets according to required assistance;
- Ability to provide updates on the situation and also receive advice until emergency services arrive.
If two-way communications are not available, then a distress beacon should only be activated in situations of grave and imminent danger. This equates to when you feel you are facing a life threatening situation. This is a personal decision that is different for everybody.
The correct way to deploy your beacon depends on the type of beacon you have and whether you're on land or water. If you are in a group, do not activate more than two beacons. If the group separates, activate a beacon in each group. If individuals drift apart, activate beacons fitted to each person. Your EPIRB should be floated (tethered) PLBs and MOBs should remain attached to your person. PLBs antennas can be rotated according to where it is mounted on your body.
𝐂𝐚𝐫𝐢𝐧𝐠 𝐟𝐨𝐫 𝐲𝐨𝐮𝐫 𝐃𝐢𝐬𝐭𝐫𝐞𝐬𝐬 𝐁𝐞𝐚𝐜𝐨𝐧
Distress Beacons don't need daily attention, but they do need deliberate care, and that care comes down to four things: how you store it, how you manage the battery, how disciplined you are about testing it, and whether it’s properly registered. Regularly inspect the device for physical damage, ensure the battery is charged, and test the activation function according to the manufacturer's guidelines. A recent, welcome development is the integration of NFC technology in devices like the Ocean Signal RescueME Personal Locator Beacon which provides users with the ability to conveniently access beacon data from their mobile phone. The simple act of placing a phone near the beacon automatically opens the Ocean Signal Product App and provides access to a wealth of usage data including current battery life, number of self-tests completed, number of GNSS tests completed, and if applicable, the amount of time the beacon has been activated. Detailed information on each self-test and GNSS test performed by the beacon is also available if desired. For each successful GNSS test, users can view a map showing exactly where the test was performed, the date and time of the test, the time it took the beacon to get a fix on your GNSS coordinates, the number of satellites the beacon used to obtain that fix, and the accuracy of the location.
𝐑𝐞𝐭𝐮𝐫𝐧 𝐋𝐢𝐧𝐤 𝐒𝐞𝐫𝐯𝐢𝐜𝐞 (𝐑𝐋𝐒) 𝐞𝐧𝐚𝐛𝐥𝐞𝐝 𝐛𝐞𝐚𝐜𝐨𝐧𝐬
Another thing you might like to consider while choosing which model of distress beacon to buy is whether it is fitted with RLS. An activated RLS enabled beacon receives an automatic acknowledgement that their 406 MHz distress alert and location has been received. When the RLS enabled beacon receives the Return Link Message (RLM) it provides the user with reassurance the distress alert has been received. This is visible on the beacon e.g. coloured flashing light. A great morale booster when you are floating around out there! Future developments may even allow for text messages like "Marine Rescue are on their way to your location"
𝐀𝐜𝐜𝐢𝐝𝐞𝐧𝐭𝐚𝐥 𝐚𝐜𝐭𝐢𝐯𝐚𝐭𝐢𝐨𝐧
If your beacon is accidentally activated, switch it off immediately and contact the Australian Maritime Safety Authority (AMSA) on 1800 641 792. There is no penalty for accidental activation if you notify AMSA or local rescue authorities immediately. If you activate your distress beacon intentionally and your situation then improves, don’t switch it off straight away. Try to establish two-way communication first, by mobile phone, radio, or 000 if it’s available, and confirm directly with authorities that rescue is no longer required before you turn the beacon off. Doing it in that order will help prevent confusion within the search and rescue system.
𝟏𝟐𝟏.𝟓 𝐌𝐇𝐳 𝐝𝐢𝐬𝐭𝐫𝐞𝐬𝐬 𝐛𝐞𝐚𝐜𝐨𝐧𝐬
121.5 MHz distress beacons are no longer detected by satellite and are no longer licensed for use. Replace your old 121.5 MHz beacon with a GPS 406 MHz distress beacon as soon as possible. Do not risk your life by relying on a 121.5 MHz distress beacon. Don’t forget to dispose of your old beacon correctly and register your replacement beacon.
𝐏𝐥𝐞𝐚𝐬𝐞 𝐧𝐨𝐭𝐞: Although the civilian aircraft emergency frequency 121.5 MHz is no longer monitored by satellite it is still used for local homing. This is why you will see a Search and Rescue vessel circling the Target or Distressed Vessel in order to accurately fix it's location. Even if you believe you have been sighted by rescuers you should not switch off your EPIRB until instructed to do so.
Summary of Frequencies Used by EPIRBs
406 MHz Primary distress alert Satellite detection via COSPAS-SARSAT
121.5 MHz Local homing signal for search-and-rescue
This dual-frequency capability enhances the effectiveness of EPIRBs in emergency situations, ensuring that both satellite and local resources can work together to locate individuals in distress.
𝐃𝐢𝐬𝐩𝐨𝐬𝐚𝐥 𝐨𝐟 𝐨𝐥𝐝 𝐛𝐞𝐚𝐜𝐨𝐧𝐬
Toll Ambulance Rescue have informed us that one of the most common causes of false alarms from EPIRBs and PLBs is from people failing to remove the battery before throwing them in the rubbish. Follow these steps to prevent accidental activation and ensure compliance with environmental regulations:
- Do Not Discard in General Waste: Never throw an EPIRB or PLB into household or general waste, as it may accidentally activate in a landfill, triggering false distress signals and wasting emergency resources.
- Deregister Your Beacon: Always deregister your beacon, contact the Australian Maritime Safety Authority - AMSA. Update your registration online at www.beacons.amsa.gov.au or by calling 1800 406 406.
- Deactivate the Beacon: Always follow the manufacturer’s instructions to disable the beacon. This typically involves removing retaining screws and separating the case to access and remove the battery. Ensure this is done carefully to avoid damaging the device or triggering a signal. Disconnecting the battery eliminates the risk of accidental activation. (refer to your specific models instructions)
- Dispose of the Battery and E-Waste: Contact your local waste management facility to find environmentally friendly disposal options for the battery, as batteries often contain lithium or other hazardous materials. GME Beacons can also be returned to GME for end-of-life disposal, either in person or by post. To organise this email the GME team at [email protected].
You can help keep our dedicated volunteers on the water by donating here: https://shorturl.at/zgYQL
Some useful links:
https://www.gme.net.au/au/emergency-safety/
https://beacons.amsa.gov.au/
https://www.nsw.gov.au/driving-boating-and-transport/waterways-safety-and-rules/lifejackets-and-safety-equipment/essential-safety-equipment
Phil's tips and tricks video on EPIRBs and PLBs https://youtu.be/qFO9qF1CY-o?si=irytP3F9t0RXA6m0
