Maritime industry homing in on EPIRBs with integral GPS

Jan 22, 2010 12:00 AM

If you’re reading this magazine, chances are you spend time on a vessel required by the U.S. Coast Guard to carry a 406-MHz emergency position indicating radio beacon (EPIRB). Chances are good, too, that the EPIRB it carries is not GPS-equipped. Exact figures aren’t known, but just a small percentage of EPIRBs currently in use have integral GPS transmitters. The Coast Guard regulates other aspects of EPIRBs, including emergency-release and automatic-activation mechanisms, battery-replacement periods and signal registration, but it doesn’t require them to be GPS-equipped.

It does recommend them, though — and may yet require them. As technological advances continue apace, there are fewer and fewer reasons not to make the leap. For one thing, the price differential between these units and their non-GPS counterparts keeps shrinking, putting them within reach of more fleets, vessels and even individuals. More importantly, a GPS-equipped EPIRB can reduce the speed with which rescuers find and act on an emergency signal by as much as 40 minutes. When crew lives are on the line — including your own — how much is each of those minutes worth?

“GPS is definitely the way of the future,” said George Lariviere, vice president of Maine-based Whiffletree Corp., which distributes an Australian-made line of EPIRBs.

EPIRBs have led to the rescue of almost 27,000 people — more than 6,000 in the United States since 1982. That’s when the international Cospas-Sarsat network of low-Earth-orbiting satellites began tracking them. When an emergency beacon transmits at a fixed frequency, these satellites “hear” a Doppler frequency shift as they pass over it. The signal’s location can then be determined by triangulation. Cospas-Sarsat satellites orbiting the poles provide reasonable coverage, especially near the equator. But an EPIRB that’s been triggered still has to wait for a satellite to pass overhead before the signal is received — once every 100 minutes or so — and for the next satellite to narrow down the location to closer than about 2.5 nautical miles.

EPIRBs using Inmarsat geostationary satellites have a faster response time, since they can be recognized within a couple of minutes of being triggered. However, there’s no location information in the signals, so all rescuers can do is begin to mobilize while they wait for another satellite to pick up the signal. This is faster, but still not ideal.

Since about 1997, some beacons have included a GPS component that can deliver a signal within about four minutes, pinpointing location to within about 100 yards. “They’re much more accurate,” said Lariviere. “The ones with GPS can be located and identified by the geostationary satellites once the GPS turns on — they can hear it the minute you set it off, but they can’t locate you until your GPS acquires.”

Charlie Bond, whose company, Ralston Cunningham Associates, is an EPIRB manufacturer’s representative, compares it to your car’s dashboard GPS, which remembers the last-known satellite location when you turn it off so it has an idea where to begin looking for satellites when you turn it back on. An EPIRB’s GPS might not have been powered on for years. When it’s finally activated, it needs to acquire satellites quickly and reliably under harsh conditions such as a sinking or storm.

“It’s not just the accuracy; it’s the speed that’s the real selling point,” Bond said. In fact, he said, the reliability of GPS has changed the way EPIRBs are used. In 2006 the U.S. Coast Guard began mobilizing and funding rescues as soon as a signal was received, making search-and-rescue responses even more rapid. With GPS, it’s no longer even search and rescue, he said, it’s just rescue.

So why aren’t more of the thousands of EPIRBs in use GPS-enabled? In a word, price.

Both Bond and Lariviere estimate that just 10 to 15 percent of International Maritime Organization (IMO) vessels have EPIRBs with integral GPS. The difference in cost used to be several hundreds of dollars per unit, which adds up when outfitting an entire fleet. That’s changing fast, though. A price comparison of different models and vendors showed a little more than $100 to $300 separating some units.

But here’s the thing: if the Coast Guard requires you to have an EPIRB on your vessel, you’re also required to change the battery every five or six years, depending on the model. Batteries can cost $300 to $400. You also need to replace the hydrostatic release unit every two years, which can run as much as $120. Replace both at the same time, and you’re more than halfway to the cost of a brand new, GPS-enabled EPIRB. Category 1 EPIRBs — which are automatically released and activated by water pressure — start around $500 without GPS and around $800 with. The new models have shrunk in size as well as price. Some personal locator beacons — which are registered to individuals instead of vessels, and which are not required to float — are no bigger than a cell phone and start around $300. This makes them attractive and affordable options for individual mariners, sailors, kayakers, wilderness hikers and snowmobilers, and especially for the private airplane pilot market. Nearly all PLBs have integral GPS. They don’t meet Coast Guard requirements for EPIRBs, but they’re being used more and more as supplemental safety measures in marine situations.

Lariviere says some IMO fleets are beginning to switch to EPIRBs with integral GPS for a different kind of emergency entirely — piracy. “It’s for the safety of the crew, as a way to notify people that they’re in trouble,” he said. “I applaud that.”

They may not yet be mandated, but EPIRBs with integral GPS are faster and more accurate, and they cost less than units (without GPS) from just a few years ago.

Get out ahead of the curve with a GPS-enabled EPIRB — or risk getting left behind. •

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