At the beginning of last season, the stroke of an official pen shut down an entire communications system and made half a million distress beacons obsolete, as the International Cospas-Sarsat satellite system stopped processing distress signals on 121.5MHz.
It wasn’t as bad as it might appear, though: the old 121.5MHz distress beacons hadn’t been doing much—other than adding to the tally of false alarms—for years. The Coast Guard had also been warning people about the impending switch-off for months beforehand, so it shouldn’t have come as any surprise.
The change has, however, prompted increased interest in 406MHz Personal Locator Beacons (PLBs), scaled-down versions of the Emergency Position Indicating Radio Beacon (EPIRBs) carried by many boats, with beacon manufacturers ACR and McMurdo both introducing new products.
ACR’s AquaLink PLB is the bigger, heavier and more expensive of the two, but it’s still less than six inches long and weighs a little under nine ounces. It includes a GPS so it can transmit an up-to-date position that should be accurate enough to guide potential rescuers to within a few yards. From there, the beacon’s new strobe light should allow them to pinpoint its location. The AquaLink’s list price is $499, but many retailers are offering it for about $400.
McMurdo’s Fastfind 210 PLB is even smaller. In fact, it is said to be the smallest 406MHz distress beacon in the world, at just over four inches long and weighing only 5.3 ounces. With retail prices around $300, it’s also the cheapest. Even so, it still includes a built-in GPS to direct potential rescuers directly to the casualty. The one thing it doesn’t have is a strobe light.
Most of us probably think of an EPIRB (or a PLB) as a distress-only device. But ACR has set up a service called 406Link that allows an EPIRB—almost any EPIRB, not just ACR’s own units—to be used to send simple text or email messages.
The new service makes use of an EPIRB’s self-test function—all EPIRBs have one—which checks that the battery, internal circuits and software are in working order by transmitting a message that is deliberately “corrupted” so as not to trigger a rescue operation.
To tap into this feature, ACR has set up a ground station that receives these test messages and sends a “Test OK” message to a nominated cell phone or email address. The original idea was simply to give owners the assurance that their EPIRB really was transmitting. But the concept has since been expanded, and for $59.99 per year the 406Link Plus service will send a pre-programmed “I’m OK” message to five email addresses and five cell phones, with a hyperlink in each message that will display the EPIRB’s position on a Google Earth map.
[ AIS DEVELOPMENTS ]
Another communications system that has blossomed over the past year is AIS (Automatic Identification System). All ships and a growing number of sailboats and small commercial vessels now carry equipment that automatically transmits details of their position, course and speed over two dedicated VHF channels. Anyone with a suitable receiver can receive this information and display it on their radar, chartplotter or computer screen, either as text or in the form of a dedicated graphic display. With a decent display, it’s probably the most powerful anti-collision tool we’ve ever had.
There are three distinct types of AIS. AIS A is the big ship version: powerful, sophisticated and expensive, it isn’t really suitable for any but the largest yachts. AIS B is the “voluntary fit” version, cut down and customized for sailboats and small craft. The third type is “receive-only” AIS, which is what the name suggests—equipment that receives information from other vessels, but does not transmit. The trouble with receive-only AIS is that it’s a bit like riding a bike without lights: it assumes that it’s fine for other people not to see you, so long as you can see them!
Unfortunately, although AIS A has been compulsory for most ships for years, the FCC didn’t get around to approving AIS B transmitters for small craft until about 18 months ago, so until last year, receive-only was all we had. Since then, there has been a flurry of new AIS B transponders, and several innovative AIS receivers.
Digital Yacht is a new name on this side of the Atlantic, but the UK-based firm seems intent on carving out a place for itself as an AIS specialist, with a range of products that include AIS B transponders, receive-only units and what is said to be the first plotter to have a built-in AIS receiver. A particularly neat product for anyone who fancies trying out AIS without making too much of an up-front commitment is the ANT 200 receive-only unit, which is shaped like a mushroom with a short helical antenna. It’s priced at $299 and is designed specifically for quick and easy do-it-yourself installation, requiring just a mounting bracket, a power supply and a standard NMEA connection to any compatible chartplotter.
Standard Horizon, on the other hand, has set off on a different tack: while relying on external AIS receivers (like the ANT 200) to supply AIS information to its chartplotters, it has integrated an AIS receiver into its Matrix VHF radio—and collected an NMMA innovation award in the process. The award citation sums it up neatly, describing the Matrix AIS as “a compact affordable combination of Class D VHF and AIS that brings two important safety and communication features into the hands of the average boater.”
The unit looks like a conventional VHF radio, but includes a bigger than average screen on which it displays a radar-like graphic or alphanumeric list of the AIS information being supplied by surrounding vessels. Perhaps the greatest advantage of integrating AIS and VHF is that you can call any of the vessels shown on the screen by simply selecting them, and then pressing the “call” button. List price is $667, but online suppliers offer big discounts.
Even Garmin has finally bitten the AIS bullet. Surprisingly, for a company that prides itself on being a leader and innovator, it wasn’t until November last year that it announced that its first AIS B transceiver—the AIS600—would be available in 2010. The system’s list price of $1,399.99 goes head-to-head with Raymarine’s AIS500, but the Garmin unit boasts one unique feature that sets it apart from competitors. For some arcane reasons every other AIS on the market uses the NMEA 0183 protocol to communicate with other instruments, while Garmin has opted for the faster and more sophisticated NMEA 2000 protocol.
While sailors and the companies that serve them are still coming to grips with the idea of AIS, the commercial boys are already moving on and finding new applications for this technology that probably weren’t even thought of when it was first suggested all those years ago.
One such idea is a portable AIS transponder, like the AIS SARTs produced by companies such asJotron and McMurdo, which could be fitted to a ship’s lifeboats or taken on liferafts, so that they show up on the chart displays of potential rescuers.
OK, so that’s not particularly clever. But how about a personal AIS transmitter that can be clipped to a lifejacket and triggered if you fall overboard? The international legislation that makes such things possible is already in place, and at least one company (Weatherdock) is already producing them.
