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Using technology to protect your boat.

The ABCs of Safety

There’s a load of protection available in this alphabet soup of electronics, And at an affordable price.

You can’t put a price on your family’s lives.” It’s a simple sales pitch that is used to sell all kinds of safety equipment from liferafts to flashlights—including some devices that are little better than snake oil. But amongst the acronym-heavy selection of electronics there are a few systems that really could be lifesavers.

Take AIS (Automated Identification System), a communication system through which a ship transmits details of her identity, position, course, speed, and other information every few seconds. Each databurst is in a high-speed code and lasts only a few milliseconds, but it’s available to anyone with a suitable receiver. There are many ways of displaying the information. The most popular seems to be to superimpose it on the chart page of a multifunction display, but some VHF radios include an AIS display, and there are also some dedicated single-purpose units. 

Most commercial ships have been required to transmit AIS data since 2003, but owners of private pleasurecraft can join in if we wish, either using Class A transponders like those used by those ships, or less expensive, lower-powered Class B transponders that are intended specifically for small craft.

The uses of AIS have expanded since it was first introduced: It is now being used to put “virtual buoys” on electronic chart displays and—soon to come—in personal distress beacons for man-overboard and missing-diver situations. Retail prices start at about $200 for a “black box” receiver and about $750 for a Class B transponder, which puts your boat on the screen of everyone around you. 

And speaking of being in touch with those around you, Digital Selective Calling (DSC) is a function that is built into all current VHF radios, which allows the transmitting and acknowledgement of calls that normally take place on Channels 16 and 9 to be carried out on Channel 70, in a fraction of the time and without disturbing everyone else in the vicinity.

Simplified routine calls are nice, but DSC radios also have a “panic button” protected by a spring-loaded cover. If you are ever in a life-threatening distress situation, press that button for five seconds and your radio transmits an automated distress call to every other DSC radio within range, complete with your position. DSC basically puts your data in the hands of those best able to offer timely assistance.

One problem: The radio can’t do that on its own! Before it can make that call, send a distress message, or tag messages with your position, it needs to have your boat’s maritime mobile service identity (MMSI) number stored in its memory, and it needs to be connected to a GPS. 

For a solution, go to to register for a free U.S.-only MMSI number or to and click on Ship Radio Stations to find out how to register for an international MMSI number. Retail prices start at around $100 for a DSC radio, and, as I mentioned, a U.S. MMSI number is free. 

So what if you’ve derived enough confidence from all this equipment to take on a bluewater passage? Then you’ll want to also bring along an Emergency Position Indicating Radio Beacon (EPIRB) or maybe a Personal Locator Beacon (PLB). These very small, very specialized satellite communicators can only transmit one message—a half-second burst of digital code giving their own unique registration number—repeated every 50 seconds. EPIRBs are larger and have longer battery life than cell-phone-sized PLBs.

In both cases, the idea is that transmissions will be picked up by one of a constellation of fast-moving, low-flying COSPAS-SARSAT satellites. By analyzing the way the EPIRB signal appears to change frequency as it flies past, the satellite can calculate where it is coming from and download that information to search-and-rescue authorities ashore. In the time since the devices have found wide use, it has not been a very accurate process, nor is it instantaneous: It may take a couple of hours to relay a position that is only accurate to a couple of miles. 

But both drawbacks are being overcome by the latest generation of EPIRBs and satellites, which can often achieve a pinpoint position, relayed within a matter of minutes. It will take the “search” out of “search and rescue,” and enhance a worldwide safety net that, even with its limitations, helped rescue nearly 2,500 people last year. Retail prices start at about $250 for a PLB and about $700 for an EPIRB, although the latter are available for rent for long passages.

Part of being safe is being seen and not only when you want to be rescued. Being seen helps you avoid getting run over. Ever since ships started using radar, recreational boaters have worried about how to make themselves more visible. Marine radar works by transmitting very short pulses of microwave energy and listening for the echoes that bounce back from solid objects—so the obvious way to make yourself more visible is by modifying your boat to reflect more energy. That’s the principle of radar reflectors, but an active Radar Target Enhancer (RTE) is a modern alternative that works by electronically copying the incoming pulse and retransmitting it. Prices start at about $600, but an RTE is much more powerful and much more consistent than a passive reflector: It virtually guarantees that you will be seen by any watchkeeper who is looking at his radar.

How much or how little of this equipment you should carry is obviously up to you. But given the moderate prices, it’s difficult to argue against the better-safe-than-sorry strategy. And if you did buy some or all of it, the odds are you’d never actually use any of it. But as insurance goes, these electronics are nothing short of a bargain.

This article originally appeared in the January 2012 issue of Power & Motoryacht magazine.