Article by Capt. Steve Katz
THE SAFETY ALPHABET EPIRB, PLB, AIS-MOB
The world’s first EPIRB was tested and approved in 1970. While Satcom and IP Based networking is the current trend for communications on the high Seas, the EPIRB remains a simple, proven device to alert rescue authorities around the clock and around the world.
Here’s a brief summary of how an EPIRB works:
•the device is deployed either automatically or manually, and then activated automatically when floating in the water or with the flip of a switch.
•once activated, the EPIRB transmits a digitally coded signal on a frequency of 406 MHz, which is received by orbiting satellites. Most current EPIRB’s on the market include a GPS sensor, allowing the EPIRB to transmit a position along with the digital data.
•the EPIRB is routinely mounted to a vessel and registered to that vessel.
•the cost of an EPIRB begins around $400.
A PLB or Personal Locator Beacon is very similar to an EPIRB, though with some significant differences. One common feature is that the PLB contacts the same rescue authorities, using the same satellite communication network. The PLB is much smaller, designed to be carried or worn by a person and is registered to a person. Not all PLB’s float by themselves. They are manually activated and most do not transmit at the same power level and duration as a traditional EPIRB. The cost of a PLB begins around $260.
MOB (Man overboard), that age old saying when a crewmember /passenger (man or woman) falls into the water is something you never want to happen aboard a boat. When this occurs, it is an urgent scenario and the person needs to be rescued as fast as possible. In addition to the traditional rescue tools, modern electronics allow the tracking of the person with ease. Most modern chartplotters have an easy to find button labeled MOB, or SOS, for the purpose of saving a position and allowing the vessel to return and search that exact area.
Some autopilots will automatically steer to an activated MOB position, allowing the crew to focus on the search. While a PLB is great if worn, the necessary equipment to receive a PLB signal is found only on search and rescue vessels, making a local search difficult.
The newest, wearable electronic safety device is an AIS MOB. When activated the device transmits an AIS MOB message containing position and ID via the AIS (Automatic Identification System). The AIS transmission will be detected by all AIS equipped vessels within range, about 2 miles on open water. This AIS MOB transmission is received by an AIS receiver and displayed on a chartplotter, quickly indicating the precise location for the overboard person. As you might already know, the AIS system is a worldwide standard, an automatic tracking system, using the maritime VHF radio frequency. The rapid adoption of AIS receivers on pleasure boats and mandatory adoption on many commercial vessels allows for good coverage in popular boating waters. The cost of an AIS-MOB begins around $299.
If you are going to carry a personal AIS device(s) you must always test it against the boats electronics to learn exactly what will be displayed on your chartplotter and if an audible alarm will be sounded by your chartplotter upon AIS activation.
While not in the same category of the dedicated safety devices, there are two popular devices that can help you communicate while out of cell phone range. Both products are small handheld, waterproof devices that are easy to use. While neither of these devices are a substitute for an EPIRB/PLB with its dedicated link to worldwide public rescue authorities (with no annual fee), the SPOT Gen3 and InReachSE both can send a message to friends and family along with your location – something you can’t do with an EPIRB/PLB.
The Globlastar SPOT Gen3, is a handheld communicator that can send (not receive) a pre-programmed message to family and friends or it can also send a SOS to a private emergency center. The messages include your GPS position, allowing friends, family or rescue authorities know exactly where you are. The cost of the SPOT gen3 is $149.
Another popular product is the Garmin Delorme InReachSE, a handheld satellite communicator. This device allows you to send and receive 160 character text messages to anyone, along with your GPS position. The device also has a SOS button that sends a message to a private rescue center. The cost of the InReachSE is $299.
As mentioned above, having an AIS receiver (or transceiver) is a good idea in these modern times. Not just for locating other vessels for navigational purposes (or see where they are fishing), an AIS can be used to locate a vessel or persons in distress and there is even some use of AIS for navigation using a “virtual buoy” as a temporary aid to navigation. The cost of a basic AIS receiver begins at $250.
With so many different safety devices on the market, finding the equipment that meets your boats needs and budget is an easy task. Additionally the small size and low cost makes it easy to provide personal safety devices to all crewmembers and guests.
Captain Steve Katz is the owner of Steve’s Marine Service and holds NMEA, AMEI and NMEA2000 certificates along with ABYC Master Technician certification and factory training from many manufacturers.