Personal AIS Beacons

Personal AIS Beacons are to pinpoint a MOB victim in the water using the beacons AIS signal.

If you fall overboard, or if someone on your boat falls overboard, standard practice is while the boat turns around to pick up the MOB (Man Overboard) someone keeps their eyes on the MOB so you can home back in on them.

The PROBLEM is keeping the MOB in sight.

One recommendation is to throw something overboard to mark the spot. (See throwable rescue devices for ideas)

However if you have travelled too far and lost sight of the MOB, or if the

Oscar Flag indicates a man Overboard, often attached to the man overboard pole on a boat
Oscar Flag indicates a man Overboard, often attached to the man overboard pole on a boat

waves are too big, or if its at night, or you never saw where they fell in, you now have a search and rescue situation, rather than a pickup.


To address this there are many electronic beacons on the market to track MOBs. These Devices are carried by each person onboard and if they go overboard, they have a beacon sending out their location, which greatly aids rescue.

Personal AIS beacons (PAB)

Homing Beaconsa look at the latest technology

Safelink R10
Safelink R10

The PAB is a homing device which sends out an AIS signal when activated. So if you loose a MOB who has one of these devices, you can track their location on your chartplotter, provided it is AIS SART compatible, (see below for further details).

Personal AIS beacons operate via the AIS system Automatic identity system . AIS signals are sent over VHF frequencies, and can be received in most cases up to 4 miles, maybe further with a higher antenna.

The PAB signal includes GPS location and a 9 digit MMSI number. Someone receiving the signal will see your exact position on the chartplotter and be able to get to you, or to relay your distress signal over channel 16.

Who will receive your distress signal? Personal AIS beacons send out a distress alert over AIS which can be received by anyone in range who has an AIS SART compatible receiver. So you can be rescued by your vessel or any vessel in the area.

As with the date of this article the Personal AIS beacon is emerging technology and its not guaranteed that if you have a AIS receiver that it will show the beacons signal. So far Raymarine, Vesper Marine, and Garmin seem to be leading the charge. Also below we look at the AIS LifeGuard.

Positives; These devices are small and easy to carry, you know if you need to use them anyone in range can rescue you. It does not matter if you drift from where you fell in as the GPS will update your exact position. Because it sends signals locally you can get picked up quickly and do not need to wait for SAR teams.

Negatives; These Personal AIS beacons (PAB) do not send a signal to Search and Rescue teams; they are purely for localized traffic. They are also relatively expensive.

SmartFind S10 (AIS) Beacon


AIS MOB tracking

The new SmartFind S10 (AIS) Beacon by McMurdo incorporates AIS with GPS technology to give rescuers precise location information of the MOB. The signal sent by the S10 can be seen on Class A and B devices and many AIS receive only devices.

Waterproof, buoyant the unit transmits both AIS and GPS data to all AIS receiver-equipped vessels and land-based Vessel Traffic Services within a 4-mile radius. It also features a flashing LED to help rescuers home in on a target. A lanyard is included so you can tether it to your clothing.

The advantage of an AIS signal coming from the device, is that the signal shows you were the device is. Many GPS man overboard alarms on show you where the person fell overboard and they in most cases drift with current and wind.

The S10 SmartFind is known as a personal AIS beacon or PAB, so you can ad it to the mix of PLB, EPIRB, MOB etc.

Cost $349, FCC approval obtained April 30th 2012.

Weatherdock AG

AIS MOB locator

EasyRESCUE is a man overboard MOB locator beacon. EasyRESCUE uses AIS signals to locate the MOB. Therefore, instead of a personal locator beacon PLB that sends a signal to search and rescue teams (SAR), the easyRESCUE uses AIS to send a signal back to the boat. This means within a very short period of time the MOB can be recovered by the boats crew without outside assistance.

AIS is a signal transmitted over VHF frequencies that carries Lat & Long amongst many other data. Weatherdock AG has used this feature to make a personal MOB safety device using AIS signals. The easyRESCUE signal of the MOBs lat & Lon can be displayed on a AIS capable GPS Chartplotter. All you would need to do is follow the course back to the MOBs position. Even if the MOB has drifted, the signal keeps updating its position.

IEC has now finalized the specification for AIS-SART beacons. EasyRESCUE sends an emergency AIS-SART sentence (MOB)which triggers an alarm on all AIS enabled chart plotters. The range of an AIS signal is VHF range. All plotters or pc’s which are equipped with an AIS-receiver will get the message from the easyRESCUE.

The easyRESCUE sends an AIS telegram type 1 which contains the position information and an AIS telegramme type 14 which is a broadcast alert telegram with a “pre defined” text, which will be “AIS SART active”

Operation; The Easy Rescue can be attached to a life jacket or to clothing via a lanyard or clip. To operate release the coiled antenna and then press ON. Regular tests of the GPS function, battery state etc can be seen with the test button.

Safelink R10


AIS MOB locator

The VOLVO round the World race is a serious undertaking even for professional sailors. The make sure the crew in the event they fall overboard, the organizers have mandated the Safelink R10 be worn. This was after one crew several years back was washed overboard. It took too long to recover him. The Safelink helps to locate the person very quickly.

The Safelink R10 does this by utilizing AIS. AIS signals are local position reports sent over VHF channels. This way anyone who can receive AIS signals in VHF range can be alerted of a MOB. The main advantage is for the boat that lost the MOB to be able to track the crewmember by them without having to resort to COSPAT. The AIS signal moves with the MOB, so if they get blown downwind the signal comes from their position not a simple GPS location of where they went overboard.

The Safelink is what is called an SART, search and rescue transponder.

If professionally fitted to a life jacket the R10 SRS can become semi-automatic in operation. The action of the life jacket inflating triggers the R10 SRS.

April 2012; FCC has approved for sale in the U.S. Kannads SafeLink R10 SRS


Recieving the AIS beacon

So those are some of the Personal AIS Beacons, so who and how can you pick up those signals?

The answer is anyone with an AIS receiver which is SART compatible and who is within 4 miles of the MOB. This could inlude the vessel the MOB came from or any vessel in the area.

Companies who have SART compatible displays;

  • Vesper marine
  • Garmin
  • Raymarine
  • Digital Yachts AIS Lifeguard

Vesper Marine

Watchmate Sounds the alarm whenever an AIS-SART or AIS-MOB is triggered. Clearly identifies them on the display and provides continuous position updates as well as bearing and range to the SART or MOB.

Vesper Marine



panbo screen shot of Garmin Plotter

Garmin plotters will be optimised to work with the McMurdo Smartfind S10 personal AIS Beacon and the Kannad Marine SafeLink R10 Survivor Recovery System (SRS). Find out more here

Ben Ellison @ Panbo has looked at how Garmin is able to display an AIS MOB alert.

Here he talks about the testing he did with Garmin and MOB SART displays.

Digital Yacht

The AIS lifeguard is a device that can recognize a signal from a SART. SARTs are emergency signal devices worn by a boats crew.

SART is the acronym for Search and Rescue Transponder. These SARTs like the Smartfind S10 AIS Beacon and the SafeLink R10 SRS are devices that a person who needs rescuing like a man overboard can use to signal their position. The SART is worn by a boats crew and if activated the SART send out an emergency signal with position.

The problem with SARTs is that not all Chartplotters and AIS receivers can recognize a SART signal. The AIS lifeguard is needed in addition to the AIS receiver and is intended to only work with SARTs. Just connect the AIS Life Guard to an on board AIS transponder or AIS receiver and you have a fully operational AIS SART man overboard system.

The AIS Life Guard detects both message 1 and message 14 (these are reserved for AIS SART messaging). As soon as an AIS SART transmission is detected the AIS Life Guard will sound an internal 95db alarm and also display a red warning light. So within seconds the helmsman will be aware if a member of the crew or passenger has fallen overboard.

MMSI numbers

You have to register the device to get an MMSI number like you would any DSC or AIS receiver. Some of these devices come pre programmed with a number. You can go on the manufacturer’s web site and assign the number to you

Register your Radio

You need to register your Radio to get the benefits of DSC. When you do this you will be given an MMSI number.

Your MMSI number is your unique identity (no one else has this number) and contains important information about you. Obtain your MMSI and program it into your radio. Be careful as you only get one shot at entering.

Links to get your MMSI number (US only). Boat US Sea Tow

It is very important to get an MMSI number and to connect a GPS to your VHF.

USCG stats see link reports that 90% of calls received had no position with the signal. Also 60% of calls did not have an MMSI identity number. This means the Coast guard received your emergency call but did not know who you were or where you were.

In the UK you will need to take a 1 day course and achieve a short range certificate (SRC). Once you achieve your SRC you will be given a MMSI number.