SOS in the Digital Age
Like GPS, the emergency position-indicating radio beacons, or EPIRBs, that first came to market in the 1980s seemed nothing less than a miracle. But that didn’t stop manufacturers from continuing to refine them in an effort to make them that much more effective.
Paralleling these efforts have been those of manufacturers using digital technology both to develop long-range alternatives to EPIRBs and shorter-range units that have improved emergency communications.
The result is a multi-layered web of interlocking and overlapping signaling systems that ensure the right people get your call for help, no matter whether you’re just over the horizon or on the other side of the world.
Since they first appeared in the 1980s, EPIRBs have become much more compact, to the point where sailors can carry a personal locator beacon (PLB), that is smaller than many handheld radios. Beacons large and small are also now available with features that both ensure effective operation and provide increased piece of mind.
EPIRBs and PLBs do essentially the same thing: they notify shore-based authorities that you are in trouble via the COSPAS and SARSAT satellite systems; they also broadcast a 121.5 MHz homing beacon to help guide search-and-rescue (SAR) teams once they are in radio range. However, they are still very different products and EPIRBs remain the beacon of choice for bluewater use. EPIRBs, for example, provide twice the transmission time of PLBs: 48 vs. 24 hours—reason enough to go with one when far from land. They are also specifically designed for marine use, while PLBs are intended for use on both land and at sea. EPIRBs are required by law to float in such a way that they will still transmit effectively. PLBs are not required to float, and even those that do float will not do so in a way that ensures effective signal transmission.
EPIRBs are required to be water-activated after they are removed from their mounts (category I EPIRBs deploy automatically, while Category II units need to be released manually), while PLBs can only be activated manually. Finally, EPIRBs must carry a flashing strobe, and while many PLBs do carry strobes, some don’t. As a result, despite the convenience of PLBs, safety experts still recommend that sailors go with their larger cousins to ensure the message gets out in an emergency situation. “Our basic advice to people is if you’ve got a boat, get an EPIRB,” says ACR Electronics marketing manager Chris Wahler.
One situation where a PLB does make sense is if you are a solo sailor on a coastal cruise. A PLB also works well as an addition to a ditch bag, in case you are separated from your boat’s primary EPIRB. Of course, if all of your crew is equipped with PLBs, so much the better—you can never have too many ways to call for help. “It’s not a game of hide-and-seek… in a distress situation when you want to bring help you want to be as obnoxiously conspicuous as possible,” Wahler says.
The new features now available don’t change the basic functionality of today’s EPIRBs and PLBs, but they do go a long way toward improving your chances in a survival situation. Back in the day, for example, an EPIRB’s self-test function consisted of little more than an LED that confirmed the unit’s battery and circuitry were functioning correctly.
Today, however, EPIRBs and PLBs are available with far more sophisticated self-test mechanisms, including e-mail confirmation of a successful test. ACR’s Aqualink PLB and GlobalFix iPRO EPIRB even have digital displays that not only let you know what the systems are up to, but also include user tips and operating instructions. For many sailors, these kinds of add-ons might seem unnecessary, but for others they can be huge morale boosters when the chips are down.
In recent years, a number of other satellite distress-signal systems have appeared, including the SPOT satellite GPS messenger, the DeLorme iReach and the Iridium Extreme sat phone. The SPOT system communicates via the Globalstar network, while DeLorme and the Iridium Extreme both use Iridium’s satellite constellation.
All three include internal GPS receivers and an SOS feature that transmits both a distress signal and your exact location to authorities at the touch of a button. The Iridium Extreme has the added advantage of allowing voice communication from anywhere on the planet, while the DeLorme permits two-way text messaging when paired with an Android phone or DeLorme Earthmate PN-60w GPS. The SPOT system is more limited, although the new SPOT Connect can be paired with a smartphone to send text messages.
Ultimately, while these systems may provide a good backup to an EPIRB, they are “communicators” first and are not dedicated marine emergency devices. Like PLBs, they are designed for use on land, which means that, while rugged, they don’t float; nor are they well suited for operation in, say, a full gale. For non-emergency situations (like letting your friends and family know all is well), these devices work well, and it certainly won’t hurt to carry one in a ditch bag—again, you can never have too many ways of calling for help. But when you’re offshore there’s no substitute for the actuate-and-forget performance of an EPIRB or PLB.
Shorter Range Signaling
Closer to shore is where VHF radios come into their own, especially those equipped with digital selective calling, or DSC, a feature available on both fixed units and some handhelds. One of the biggest advantages of a VHF radio is that your distress call can be received not just by SAR professionals, but by anyone else in range who has a VHF radio on. A DSC radio is an especially effective distress tool, because it transmits an unambiguous signal specifying a boat’s name and location.
A VHF radio is also extremely valuable after a SAR team arrives and allows you to discuss how exactly they will help you out. For this reason, many sailors include a small handheld VHF in their ditch bags. In addition to helping you organize a rescue, you can can use it guide a helicopter or ship to your exact location, since it will be much easier for you to see them than vice versa. Chucking a floating handheld VHF over the side in a man-overboard section, so that the victim can guide you to his or her position if you lose visual contact, is another good idea.
The downside to VHF is its limited range. Even a fixed radio will have a range of 20-25 miles or less. Therefore, if you plan to venture much farther offshore, an EPIRB or PLB also makes sense, even if you don’t plan on cross ing an ocean. “Once you get beyond the dinghy, I put equal importance on having a PLB onboard, complementing a VHF,” says James Turner, product manager for the UK-based beacon manufacturer Kannad. “I’m not sure I’d want to go outside, say, Chesapeake Bay without one.”
Another downside to VHF radios is the possibility of human error. Historically the problem was unclear or incomplete voice mayday calls. Today, the issue is that sailors may fail to install their radios correctly (including hooking them up a GPS), or may fail to input the correct Maritime Mobile Service Identity (MMSI) number. According to the U.S. Coast Guard, as many as 90 percent of the DSC distress calls it receives are from radios that have not been correctly connected to a GPS. As a result, is the signal includes no position information. Similarly, nearly two-thirds of DSC radios do not have proper MMSI numbers. Do not be one of these sailors!
Although it’s tempting to think of a cell phone as an effective signaling device, it would be foolhardy to rely on one exclusively. Like a VHF radio, a cell phone has only limited range, even in areas replete with cell towers. There are also no cell towers offshore, while a VHF radio works even when land is well over the horizon.
The other serious drawback to cell phones is that you need a number to dial. Granted, you can phone home or call up the Coast Guard. But what about that nearby sailboat, or that freighter bearing down on you, or that bright orange helicopter hovering overhead? “I get this question from people all the time asking me why they need VHF. I tell them, I can’t call you if I don’t know your cell phone number,” says Standard Horizon executive vice president Jason Kennedy says.
One new short-range signaling technology that does hold tremendous promise is Kannad Marine’s SafeLink R10 SRS, a small personal beacon that allows a boat to home in on MOB using an onboard AIS receiver. Small enough to attach to a lifejacket, the SafeLink R10 even includes a small GPS receiver and can provide rescuers with not only the distance and bearing to a victim, but also an exact lat-lon position.
According to Kannad’s Turner, the system has a nominal range of 4 miles and is especially effective in rough conditions, since it transmits eight times per minute, which means signals are sent from wave crests as well as troughs. For years manufacturers have been trying to develop different onboard homing systems involving various types of antennas and receivers. But by harnessing an existing robust technology like AIS, Kannad has created a device that is effective and elegantly simple.
At press time, the system had received Federal Communications Commissions approval here in the United States, but was still waiting for Coast Guard approval. Hopefully, that won’t be long in coming.
Rescue photos courtesy of U.S. Coast Guard; illustrations by Andy Steer