If you've ever had to call the Coast Guard, you know that the nation's oldest sea service is ready to do whatever it takes to rescue you – from dispatching fast-response boats and helicopters to lowering rescue-swimmers into heavy seas to pluck you from the water.
Assuming they can find you, that is.
For Coasties, locating boaters who are in distress is often the toughest part of search-and-rescue operations. Many boaters don't know where they are when they get into trouble, don't have marine radios or don't know how to use them. Those who abandon ship can get swept away by strong currents. Finding you can take hours of searching by aircraft or patrol boats – and sometimes that's too long.
This year the Coast Guard is equipping its shore stations with a new state-of-the-art communications system called Rescue 21. It can detect even faint SOS calls more effectively and use them to pinpoint the location of boaters immediately, enabling rescue crews and helicopters to reach them more quickly.
"Rescue 21 is helping the Coast Guard take the 'search' out of 'search and rescue,'" says Admiral Thad Allen, the Service's commandant. He calls it "a quantum leap forward in command, control and communications" that will cut the Coast Guard's response-time in rescue cases, save more lives and reduce the risk to Coasties themselves.
A LARGE INVESTMENT
The $550 million direction-finding and communications system, which will replace the outmoded equipment that has been in place since the 1970s, is now operating in 12 of the Coast Guard's 35 sectors, covering 15,745 miles of coastline, navigable rivers and waterways in the continental U.S., Hawaii, Alaska, Puerto Rico and Guam.
US COAST GUARDThe Rescue 21 system relies on large towers to increase the Coast Guard's reach. 
U.S. COAST GUARDThe Rescue 21 system is running in 12 of the Coast Guard's 35 sectors.
The service plans to install it for the remaining 79,525 miles of shoreline and waterways by the end of 2011.
The full cost, when the system is completed in 2017, will total about $1.1 billion, Coast Guard officials say.
The Coast Guard says it hasn't tried to estimate how much the new system would save the service – either in time or money – because the calculation would be unusually complex, and might not be very accurate.
Since each rescue effort is different, it's difficult to add up how much time the service would save in a particular incident, says Lt. Commander Brian Anderson, project officer for Rescue 21 at Coast Guard headquarters in Washington. "It would take a significant amount of research," he says.
Moreover, the new system's vastly improved listening capability already is enabling the Coast Guard to pick up distress calls that it otherwise might have missed entirely – which leads to more time spent on rescues, though with significant benefits to those who are in distress, Anderson says.
NEW FEATURES
Besides direction-finding equipment, new Rescue 21 installations contain extra-sensitive VHF-FM and ultra-high-frequency radio transceivers; chartplotter-style graphic-interface units; recording equipment that can tape and play back distress calls while filtering out background noise; and special devices that can patch a vessel's radios into shoreside telephones, enabling boaters to get direct medical advice.
By contrast, the old installations had no direction-finding capability, were riddled with gaps in coverage and were unable to deal with more than one radio call at a time. Coast Guard watchstanders had to make rough guesses about a boater's whereabouts. And the system wasn't fully compatible with equipment used by other first-responders, such as marine police or private rescue boats.
Rescue 21 corrects all these flaws, officials say, and also enhances the clarity of distress calls, allows even the small local rescue-stations to monitor more than one channel at once, and extends the range at which Coast Guard radio operators can transmit and receive voice messages.
DETERMINING LOCATION
The speed with which Rescue 21 can locate boaters in distress is stunning. If a boater merely keys the microphone on his VHF-FM radio for a second or more, the system can draw a straight line from a nearby communications tower to the radio antenna of the vessel in distress, narrowing the area along which rescuers need to search. A signal from a second tower – or efforts by a skilled Rescue 21 watchstander who can manipulate the software – can provide an intersecting line, enabling the Coast Guard to find the boat's exact longitude and latitude.
Rescue 21's plotting capability also vastly reduces the time it takes for the Coast Guard to compute how far the boat (or the boater) is likely to drift during various weather, wind, current and tidal conditions – a key factor in any rescue effort. Under the old 1970s system, it often took three to four hours to estimate such movements. With Rescue 21, the whole process takes no more than three to five minutes.
PLOTTING SEARCH PATTERNS
The system not only predicts where the boat (or the boater) will end up over the next few hours, but it also plots out the search pattern that a patrol boat or helicopter should follow in looking for the person or the vessel. It provides rescuers with exact coordinates on where to begin the search and how long to stay on a particular course before turning to follow the next leg of the search pattern.
Watchstanders use high-tech communications data to pinpoint boaters in distress.The new system also will bolster the Coast Guard's ability to carry out its homeland security missions – by operating more closely with other armed services as well as with federal, state and local homeland security agencies throughout the United States. And in the 48 contiguous states, it provides portable radio towers for use during natural disasters.
MORE SENSITIVE, EFFECTIVE
By the Coast Guard's own account, the new system already has proven to be dramatically more effective than the one it's replacing. It's able to pick up radio calls that the current equipment misses entirely or home-in on faint static from a keyed microphone, and transmit the information to nearby vessels.
Finding boaters in distress isn't always easy. Coast Guard rescue personnel must spend hours – sometimes days – locating vessels and boaters who have called for help themselves or have been reported by others as missing or in trouble. It often requires scanning large areas of water from patrol-boats or helicopters.
In some cases, mayday messages are garbled. Boat radios fail to transmit clearly or far enough. Boaters who fall overboard frequently are swept by wind and currents to locations far from where they entered the water. Rescue 21 won't overcome those problems entirely, but it is cutting response times in many cases, officials say.
Last month Coasties rescued a 78-year-old man who'd been drifting in a life-raft 20 miles off the Florida coast. Although his small hand-held radio had a transmitting range of only about five miles, Rescue 21 equipment picked up the signal anyway and pinpointed the life-raft – some 15 miles away from where the man had said he was.
A few days before that, the Coast Guard rescued a seven-person crew whose members had become disoriented in the fog off the coast of Wildwood, N.J., after the vessel's GPS receiver had become disabled. Coast Guard radio operators located the 22-foot boat with Rescue 21's new direction-finding equipment.
"Our call traffic has increased significantly in sectors where Rescue 21 has been installed," says Lt. Commander Anderson. "We get more cases because more people are able to reach us – and we're able to locate them more quickly."
GETTING YOUR OWN BOAT READY
Technically, if you already have a VHF-FM marine radio, you won't have to do anything more to equip your boat for Rescue 21. Your existing radio will do the job, and the Coast Guard plans to continue using Channel 16 as the primary channel for emergency distress calls.
But the Coast Guard stresses that you'll get a more effective response if you buy and install a VHF-FM radio equipped with Digital Selective Calling, or DSC. When DSC has been linked to your GPS set or LORAN receiver, it enables you to push a button that automatically transmits your exact position, a description of your vessel and the nature of your distress to the Coast Guard.
The same message also goes to all DSC-equipped vessels in the area, including commercial and recreational vessels. Big ships are required to monitor Channel 70, which carries DSC transmissions, and some towboat companies are equipping their boats with DSC radios. As a result, the Coast Guard can tell which other vessels are in your area when you get into trouble, and ask them to be on the lookout for you.
To make a DSC radio fully effective, you must do two things: register the transceiver and obtain a Mobile Maritime Service Identity (MMSI) number to program into it, and then hook the transceiver up to your GPS set or LORAN receiver. You can both register and get your MMSI number through BoatU.S..
If you already have a Federal Communications Commission license for your VHF-FM radio – not required unless you take your boat to foreign countries – your documentation probably contains an MMSI number. All you have to do is program it into your DSC radio (see your owner's manual for instructions).
Anderson says the next step is to educate the boating public about the new system – particularly on the benefits of buying a VHF-FM radio with the Digital Selective Calling feature and hooking it up to their GPS or LORAN sets. "It's the best thing that people can do to help themselves," he says.
Art Pine is a veteran journalist who has served as a Washington correspondent for the Baltimore Sun, the Washington Post, the Wall Street Journal, and the Los Angeles Times. He is a longtime Chesapeake Bay sailor and a Coast Guard-licensed captain.