Why 406 MHz Beacons Are Better than 121.5 MHz Beacons

Hopefully by now, most people have some knowledge of this fairly new satellite technology.

So, what exactly is a 406 MHz Beacon? Simply put, it’s a lifeline! It connects you in-directly to your rescuers. You turn it on, and within minutes it relays who you are, your phone number, what type of vessel you are in, and your precise LAT/LONG position.

Things have changed since my (pre-406MHz) aviator days in the U.S. Coast Guard. When we searched for a 121.5 MHz signal, we usually picked up the “whirl” sound made by an EPIRB on our aircraft radios at about 15-20 miles from scene. The Coast Guard HC-130s had a direction finder (DF) that locked on to the 121.5 MHz signal and the plane literally flew itself (autopilot) to the source of the signal.

As many of us know, the 121.5 MHz beacon became the toy of many false alerts by pranksters causing millions of wasted taxpayers dollars. There was no way to identify the user, or the validity of the case. I can’t tell you how many long sleepless hours I spent within my twenty-three years looking for false alerts from 121.5MHz beacons!

When the 406 MHz beacon came about, it was set up to be registered to a user. The registration requires you to enter your name, and home phone number. When a 406 MHz distress signal is received, the command center will call your entered phone number to inquire on the signal prior to launching. If no one answers, they launch. If someone answers the phone, they can obtain the information needed to start the search or to cancel. By the way, many of the calls are canceled due to accidental turn-on during testing. This phone call not only saves you many tax dollars, but it can also save valuable battery time on your PLB or EPIRB if deployed accidentally.

Soon after the 406 MHz technologies came about, the FCC mandated that the power on the 121.5 EPIRBs be reduced from 75 mill watts to 25 mill watts. This reduction of power was brought about because of the “Whirl” radio sound that I mentioned earlier. The “Whirl” bled over on the other channels and became very distracting during a rescue. I suppose another reason would be is that they no longer needed that much power since the satellites no longer tracked them. The newer (lower powered) 121.5 MHz beacons are now used as man-overboard alerts and they work great for vessels with 121.5 DF systems such as the ACR Vecta series direction finders.

The U.S. Coast Guard is currently outfitting their aircraft, cutters, and small boats with new and advanced 406 DF equipment. The 406 MHz signal is much stronger and clearer than the previous 121.5 MHz signal, and in fact, a 406 DF outfitted Coast Guard aircraft flying at 24,000 feet can now pick up and lock on to the signal from a 406 beacon as far as 150 miles away!

Along with this technology, 406 DF towers are being positioned around the U.S. coastline to assist in close to shore cases. It has been determined that ninety-percent of the SAR/SAT cases happen within 20 miles of shoreline. These towers will pen point your position even faster for surface rescue resources.

PLBs are continually getting smaller and better. The prices have now dropped below $300.00 for a 406 MHz PLB with GPS and they are getting smaller and smaller. You can now place a cell phone sized 406 MHz PLB in your pocket or on your lifevest without even knowing it’s there. By placing the PLB on your person, you are assured that the 406 MHz signal directs the rescue party to you and not just to your vessel. In many cases, a beacon would direct rescuers to the vessel, but the occupants had abandoned ship and were not with the vessel. The vessel gives the searchers a base point to search from, but finding a person in the water (P.I.W.) without signals is not as easy as some might think, and in many cases, the P.I.Ws are never found.

The technology is out there and it continually gets better. It befuddles me as to why so many people ignore the possibility that an event could happen to them. It only takes a second for your world to turn from good to bad. Placing a 406 MHz beacon along with other close-up signaling equipment such as a sea dye marker or signal flag on your person, is the safest way to ensure a good outcome.

By Randy Boone

Wait! Where are you putting that EPIRB?

A recent case with the four football players in Florida has prompted many to purchase safety and survival supplies for their boats. One Tampa Tribune article mentioned how the marine stores were being flooded with customers stocking up on safety gear. Here are a few of my thoughts about this particular case.

Many (forums, bloggers) said they should have had an EPIRB on their boat.

I question if an EPIRB would have helped in this particular case.

My point. On a small boat such as the 21 footer (that these men were in), there are only one or two locations that an EPIRB would be placed or installed. On the sides of the mid console bridge or in a compartment in the bridge area.

There are two types of EPIRB deployments. Automatic (Category 1) and Manual (Category 2). With an immediate flip over, the EPIRB would remain in it's holding bracket throughout the entire flip-over. If the EPIRB is an automatic deploy (Category 1) there may or may not be enough submersion (13-15 feet) to activate the hydrostatic release. Then, lets say that it did release. Where is the EPIRB going? Right in the middle of the overturned boat! This EPIRB now has two fairly thick layers of fiberglass and a thick layer of foam blocking the signal. The EPIRB is a very valuable tool but it has two drawbacks, it must have clear view of the open sky and the antenna cannot be submersed.

Now it's possible that had one been on board the above mentioned boat, depending where mounted, it may have been retrieved the same way that the life jackets were retrieved, but a loose EPIRB would have been very difficult to locate. I would'nt recommend, nor does the U.S. Coast Guard, for anyone to swim under an overturned boat. There are many obstacles that could snag you or the back of your clothing.

Placing a Category 2 holding bracket on the console means that you have to physically remove the EPIRB. In this particular case, the EPIRB would have remained in the bracket, up-side down and totally useless. Again, you are taking a dangerous risk by swimming under an overturned boat to retrieve it.

By placing a Personal Locater Beacon (PLB) on your person, attached to your belt, in your pocket, or attached to your lifevest, it is with you no matter what. You will be saying "I'm glad I have it, instead of I wish I had it".

Some may question the ability of the PLB compared to the much larger EPIRB. They both put out 5 watts of power, they both alternate 406MHz and 121.5MHz and they both are designed to reach overpassing satellites, and within sight searching vessels. The distinguishing characteristics of the EPIRB is that it can be mounted on a vessel, and can be automatically activated by submersion, it floats with the antenna up and out of the water (with the exception of a few splash overs from waves), and it operates for 48 hours. The McMurdo FastFind Max-G PLB floats, and operates for 48 hours. The only distinguishing difference, is that it is attached to you instead of attached to a overturned vessel.

Now granted, because of the size of the EPIRB and higher placement of the waterproof antenna, it will operate much better than a floating PLB. Therefore it is recommended that the PLB be placed up and out of the water. Secure it to the top (outside) of your liferaft or attach it to a upper part of your lifevest. The U.S. Coast Guard helo crews carry PLBs in their lifevests. They have Velcro attached to to top of the helmet to place the PLB.

Is Your Personal Locater Beacon (PLB) a Passive or Active Signal?

There are two types of signals, Active and Passive. An active signal is one that you have to operate, such as aiming a signal mirror or firing a aerial flare. In either case you have to actively use your hands and attention to operate it. 

A passive signal is one that you deploy, then leave it alone, allowing you to use your hands and attention elsewhere. An EPIRB once activated is a passive signal. You turn it on and let it float while attached to you or your liferaft.

So here's the question. Is a PLB an active or passive signal? I say on land it is a passive signal, but in the water, it becomes an active signal. Well wait you say, my PLB floats!

Here is what you need to know about floating PLBs.

Although a PLB may be designed to float, it does not mean that it will stay upright, or that the antenna will stay above the waterline. Why is this important? Because the PLB will not send a full signal as long as the antenna is submersed in water! By submersing the antenna (no matter how deep), it cuts the signal transmission enough that it probably will not reach the satellite. If you think that a floating PLB is going to stay upright, and the antenna is going to stay dry with waves crashing over it, you are sadly mistaken. 

So let's get the PLB up and out of the water. You have a choice, either you can hold it up in the air, making it an active signal, or you can attach it to a high point (up and out of the water) on your person.

The U.S. Coast Guard helicopter crews have attached a piece of Velcro to the top side of their helmets where they stick the PLB.

Since you probably don't use a helmet, you can attach a piece of pile (soft side) Velcro w/adhesive to an area on your lifevest bladder. To do this, you must open the lifevest casing, exposing the bladder. Place a 2x2 piece of pile Velcro (soft side) in the area close to where your head comes out (see picture). Then add the "hook side" (coarse side) of the Velcro to the back of the PLB.

Most PLBs come with a attachment line w/ a small halyard type clip on the end. This attachment line (See Picture) should be used as a "back-up" in case the PLB comes loose from the Velcro in a heavy sea state.  Note: I have jumped from a diving board several times with the smaller McMurdo FastFind 210 PLB on Velcro and it did not come off.

By placing the PLB in this location, it becomes a passive signal, allowing you to use both hands for other functions, and because of the PLB placement, you can keep an eye on it as well.

There is only one way to ensure that you have a PLB to attach to a lifevest. By wearing a lifevest with a PLB attached. I see many boaters that keep the PLB in a separate place. This only causes you to grab one more item prior to going overboard. If the PLB is already attached to your lifevest, and you are wearing the lifevest, you will have both hands free for the egress and the lifevest and PLB will be there for your survival. Once you find yourself in the water, inflate the lifevest, pull the PLB out, activate it, and place it on the Velcro on the bladder, then attach the back-up line to the vest. You now have a passive PLB signal, allowing you to use both hands to perform other signaling functions such as using a signal mirror to vector searchers to you.

Marine Survival Technologies sells a 5"x5"x 1.5"  Deluxe Lifevest Signal Kit with the McMurdo FastFind 210 (406MHz) PLB with all components for attachment it to a inflatable lifevest bladder.

Click here for more info.