Types of Emergency Beacons (Local, PLB, EPIRB & AIS)

By: SurvivalAtSea.com | Liferaft Services

There are many reasons why you might need to call for help when you're out on the water, and there are several different products designed to do just that. Choosing the right one will depend on several factors, including the type of boating you're doing and how far from shore you might find yourself. No matter where you're going, or the size of your budget, there is an emergency beacon that could make your time out on the water safer and more enjoyable. This article will help educate you on the different types of emergency beacons that are available and why you should never leave the dock without one.

Local / Bluetooth (Overboard Location Alert System or OLAS)

So first up is a line of products from ACR Electronics called OLAS, or Overboard Location Alert System. OLAS is a suite of products designed to alert you or someone back onshore if there is a Man Overboard situation. You can start building a system with as little as one OLAS transmitter and an app on your phone or tablet. The transmitter is linked to your mobile device through Bluetooth, and if the transmitter gets too far away, it will set off an alarm and mark the last known GPS location in the app to help you navigate back to the spot the connection was lost. So basically, if someone is wearing this and falls overboard, an alarm will go off with directions back to their last known location so they can be rescued.
If you're by yourself, you can set up the app to automatically send a text message to someone of your choosing to send them your last known GPS coordinates. The system can be expanded to up to 15 transmitters with the OLAS CORE base station, and the range can be extended using the OLAS Extender for boats up to 80ft. The OLAS Guardian can also be used in place of the CORE to allow up to 15 users, but with the additional functionality of a wireless engine kill switch. You have two choices for transmitters; The watch-style OLAS Tag or the OLAS Float-On, which doubles as a wearable water-activated strobe and LED flashlight.
The transmitters can be worn by people or attached to pets or other objects you don't want to lose (like your Yeti cooler full of drinks). So, OLAS is a great entry-level system that you can start with less than $100, or you can expand it up to 15 people and boats as big as 80 ft.

PLB - Personal Locator Beacon

Next in line, we have the Personal Locator Beacon or PLB.
PLBs have been around for a long time, and it still amazes me that everyone that owns a boat doesn't spend the $300 to have one of these. Starting at about $300, you can have a direct line of satellite communication to the Coast Guard or search and rescue services that will work just about anywhere in the world that you can see the sky. Not only that, there are no subscription fees, and the batteries last for at least five years without the need for any maintenance at all. So if your boat's sinking, on fire, if there's a medical emergency, or you come across someone else that's having an emergency, you simply push a button. The Coast Guard or SAR will know your exact GPS location within a few minutes and start sending help. You get all that without a subscription fee, just the purchase price of the PLB, and a battery that will last for 5 to 7 years. The only thing you need to do is register the PLB with NOAA, so they have some emergency contact phone numbers and know who it belongs to.

The first thing they will do when a signal comes in is call the phone numbers that you registered to make sure it wasn't an accidental activation. If they can't get ahold of you, they will start sending the cavalry to your location. A PLB is one of the most powerful pieces of safety equipment you can buy for the money and, in my opinion, should be on everyone's boat before they leave the dock. We could remove the "search" from "search and rescue" if everyone had a PLB.

EPIRB - Emergency Position Indicating Radio Beacon

The full-size cousin of the PLB is the EPIRB or Emergency Position Indicating Radio Beacon. EPIRBs have been around the longest and have come a long way since they were first introduced. An EPIRB essentially does the same thing as a PLB, but with a few added features. The two most notable differences are that a full-size EPIRB is larger than a PLB, so there's more room for a bigger battery which means a longer operational life once the unit is activated. In general, a PLB will have at least 24 hours of transmission time once activated, while an EPIRB will have a minimum of 48 hours. There are differences between specific models, and the actual transmission time is usually longer than listed, but that's a general rule of thumb. The second big difference is that an EPIRB will automatically turn on if placed in water (as long as it's out of its bracket), while a PLB can only be activated by manually pressing a button. In fact, one of the requirements for PLBs is that they need to have two-step activation to help prevent false alerts. For example, ACR's ResQlink PLBs need to have the antenna flipped open first to expose the power button.

There are two categories of EPIRBs, Category I and II. The EPIRBs themselves are actually the same between CAT I and II; the type refers to a difference in the mounting bracket. A Category I EPIRB is enclosed in a plastic housing that gets mounted to the outside of the boat. If the boat were to sink underwater, a hydrostatic release allows the cover to pop off, and the EPIRB will float to the surface of the water and automatically turn on to start broadcasting a signal. A Category II EPIRB is in a manual bracket mounted inside the boat for easy access in an emergency. If the boat sinks with an EPIRB in a Category II bracket, the EPIRB will not turn on and will sink to the bottom without ever sending a signal. On certain commercial vessels, usually over 36 ft, a Category I EPIRB must be carried onboard. Recreational vessels can choose to have either a CAT I or CAT II EPIRB; there is no requirement for most recreational vessels, at least for now. Some of the best options for new EPIRBs include ACR's GlobalFix V5 and V6, Ocean Signal's EPIRB1 and EPIRB1 PRO, and McMurdo's Smarfind G8 lineup. The most exciting thing in the EPIRB world within the last couple of years is McMurdo's introduction of the Smartfind G8 with built-in AIS. Soon to be a requirement for larger commercial vessels, EPIRBs with AIS provide an additional layer of safety and opportunity for a more localized rescue.

AIS stands for Automatic Identification System and has been in use for quite a while as a system to share information between vessels in a relatively localized area. Once primarily used by larger commercial vessels, many smaller recreational vessels are installing AIS systems on board to see and be seen by other vessels in their area. Vessel information is usually displayed on a chart plotter or GPS screen and can provide information like vessel name, course and speed, call sign, and so on. When an EPIRB is activated and has built-in AIS like the McMurdo G8, the standard 406 MHz satellite signal is broadcast along with an AIS distress alarm to all vessels within range of the AIS signal. The distress alarm will show up right on the other vessel's chart plotter screens with details about the alert and hopefully offer quicker assistance than waiting for Search And Rescue teams to arrive. So now you have the best of both worlds with satellite communication to the Coast Guard and the potential for other boats in your area to come and assist you even faster.

AIS - Automatic Identification System

Finally, we have the AIS beacon. An AIS beacon works off the same principles as the EPIRB with built-in AIS described above, but without the 406 satellite signal. The AIS signal will only work within about a 5-mile radius, which is fine if you're boating near other people or trying to keep track of individual crewmembers if there's more than one person on board that could go back and make a rescue. You can think of the AIS beacon like the OLAS system we talked about earlier but more powerful. If you read our other article on PFDs, we mentioned that these AIS beacons could be installed inside an inflatable life jacket and set up to turn on automatically if someone falls overboard. Some PFDs have dedicated mounting tabs for AIS beacons, while others need some slight modifications to make it work. With the beacon installed correctly, the action of the inflating life jacket will trigger the AIS beacon causing it to turn on. Suppose you have an auto-inflating PFD with AIS correctly installed. In that case, you end up with a completely automatic system to keep someone afloat and signal for help, even if the person is unconscious or otherwise incapable of doing it on their own.
This is the ultimate system to keep track of people on board, especially on larger boats where you might not have eyes on everyone all the time. ACR offers the AIS Link MOB, Ocean Signal has the MOB1, and McMurdo offers the S20 or the S10, which is waterproof down to 60 meters and can even be used by divers.

That covers the basics about emergency beacons. All of the products we covered do not require any additional subscription plans, and they all have at least five years of battery life without any maintenance. These products are intended for emergency use only, but if you're looking for more of a two-way communication device, you can find those here: Satellite Messengers