Emergency Beacon Basics – EPIRB / AIS / PLB / PAB? What’s the Difference?

REPOSTED FROM ALL AT SEA MAGAZINE – See original post here

Emergency positioning beacons can be the single most important piece of equipment aboard should something go catastrophically wrong. When all other means of rescue have failed having one goes a long way to assuring you and your crew can come away with your lives intact. Thanks to these beacons countless lives have been saved from dire situations such as sinking, medical emergencies and accidents. As the technology and features have improved and prices have come down, there really is no good reason not to have one aboard. Whether you are on a SUP or a superyacht there are many options available and at price points just about everyone can tolerate.

Deciding which beacon is right for you is not as complicated as it first may seem. There are three popular types of beacons available to boaters. The EPIRB (Emergency Position Indicating Radio Beacon) is probably the most widely known variety. Then there is the PLB, or Personal Locator Beacon, a generally smaller beacon that can be carried with you rather than mounted to the vessel. The least known and newest beacon available to boaters is the PAB, or Personal AIS Beacon. Unlike the previous two this beacon transmits to vessels nearby rather than to a satellite network. Selecting which of these is best for your needs depends on your application.

ACR's ultra-compact and floating ResQLink+ PLB. Photo: Glenn Hayes

ACR’s ultra-compact and floating ResQLink+ PLB. Photo: Glenn Hayes

The EPIRB is a marine-only beacon registered to a specific vessel that can transmit a mayday signal to an international network of satellites and terrestrial towers. They in turn relay your message and identification information to a central communication center. There, monitors on watch are able to determine the owner of the EPIRB and will contact the list of registered emergency contacts associated with the beacon. By doing so they can identify your itinerary and dispatch the closest and most appropriate search and rescue operators to quickly and effectively initiate a rescue. The beacon is registered to the vessel and is usually attached to the boat via a mounting bracket. A Class 1 EPIRB would be encased in a special enclosed housing/mount armed with a hydrostatic release. These Category 1 units are designed to automatically activate and release from their bracket once submerged but can also be manually deployed and activated if needed. Upon submersion (anywhere from three to 12 feet depending on model and manufacturer) they are released via a spring-loaded mechanism and float to the surface, beginning transmission to the Cospas-Sarsat network of government monitored satellites. When considering one of these units it is important to remember that they need to be mounted in a location where they can float free and not become entangled in rigging even if the vessel is inverted. Another variety is the Category 2 EPIRB. These are also mounted to the vessel via a bracket but need to be manually removed from the bracket in order to float free and transmit. On most a simple flip of a switch will begin transmission.

Emergency Beacon Basics – EPIRB / AIS / PLB / PAB? What's the Difference? 1

One of ACR’s Category 1 automatically deployed EPIRBS.

Generally the largest of the emergency beacons available to boaters carry a larger battery that is capable of transmitting for longer periods of time than their smaller brethren, the PLB and PAB. These larger units also have some of the highest transmission wattages of available beacons, allowing the signal to penetrate through heavy cloud cover with ease. Varieties can include built-in GPS units to not only transmit the distress signal but also GPS position, bringing your location to a very tight circle for search and rescue efforts. These units are proving to be more popular and in some cases no more expensive than others that have GPS interfaces that require hardwiring an external GPS to the beacon, or no internal GPS at all. When considering a unit the minor added cost of an internal GPS can translate into a more rapid rescue as the search area is narrowed significantly. Some varieties of these beacons have display windows indicating operation rather than using LED lighting, and still others have a user replaceable battery such as the ACR Global Fix V4 that does not require the unit to go back to the factory for replacement, a feature we will see on more models in the future.
Personal Locator Beacons (PLBs), are becoming increasingly popular and come at a price point that fits many budget-minded boaters. These beacons are different from their larger brethren because they are registered to the individual rather than the vessel. This means you can take them from boat to boat, on backcountry trips, hunts or anywhere you feel you might need to summon help. Just like their larger cousins they are to be used only in life threatening situations where no other option is available. PLBs must be manually activated by pressing or flipping a switch and will work in the same manner as EPIRBs transmitting your distress to search and rescue operators. These handheld beacons are very compact and can be easily attached to one’s lifejacket, belt or even in a pocket.

Emergency Beacon Basics – EPIRB / AIS / PLB / PAB? What's the Difference? 2

When considering one of these it is important to remember that some will not float on their own and need a flotation case. If yours is one that needs a case make sure it is installed in it. The last thing you want is to drop it overboard and watch it sink along with hopes for rescue. The internal batteries in these units need to be replaced by the manufacturer or a certified repair facility and have a shelf life of five to seven years depending on model. Most have self-test modes and on some this mode can act as a way to send a limited number of predetermined text messages to up to five recipients. ACR offers this service with most of its PLB units for an annual subscription. If these messages are not important to you then there is no subscription required and there are no fees.

A hybrid beacon that works similar to a traditional PLB is the SPOT GEN3. This is a small handheld beacon that operates via a private network of satellites dispatching search and rescue in a similar manner to the beacons mentioned above. These units also have added features available depending on the chosen subscription, such as tracking for third parties, a check-in feature that lets others know you are OK, and even the possibility of contacting non-emergency help such as a towing service. All of these added features come at a cost by way of higher subscription rates.

Emergency Beacon Basics – EPIRB / AIS / PLB / PAB? What's the Difference? 3ACR’s GlobalFIX PRO

The newest form of emergency beacon is the PAB, or Personal AIS Beacon. These are designed to be attached to your life jacket and can be activated in an emergency once overboard. They transmit both GPS location and AIS (Automatic Identification System) data showing bearing and distance. Vessels with AIS receivers within approximately a four-mile radius can see your distress call and respond. These work well in areas with heavier boat traffic but do not have the range or capability of a PLB or EPIRB. Effective on every crew members’ life vest they are a great addition to any vessel for man overboard situations.

No matter which you choose (or better yet, you equip your vessel with one of each type) the simple fact is this equipment saves lives and might just be the most important piece of equipment on board if needed.

Glenn Hayes is a freelance photographer and writer living in west central Florida, specializing in marine and location photography, commercial, editorial and fine art work. Visit: www.HayesStudios.com