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‘World’s smallest’ PLB gets FCC OK

ACR’s AquaFix 406 GPS personal locator beacon can be attached to a life jacket

Safety products manufacturer ACR Electronics has received final Federal Communications Commission approval for what the company is calling “the world’s smallest and most functional” personal locator beacon.

The wearable AquaFix 406 GPS personal locator beacon uses the same satellite system as an EPIRB and serves the same basic purpose: to alert rescuers to the location of a boater in peril.

Chris Wahler, ACR director of marketing, says there are three basic differences between an EPIRB and a PLB. An EPIRB, which automatically activates when it comes into contact with water or can be manually activated, floats upright in a transmitting position; a PLB, on the other hand, needs to be manually activated and held in a transmitting position with the antenna out of the water. Second, an EPIRB’s battery lasts long enough to transmit a distress signal for up to 48 hours; a PLB will transmit

its signal for 24 hours. Finally, an EPIRB is equipped with a strobe light. PLBs also are smaller than EPIRBs,

easier to carry and less expensive.

One way to think of it, Wahler says, is that the EPIRB is for the vessel and the PLB is for the crewmembers. “If you’re going to spend a lot of time offshore,” says Wahler, “you should have [both].”

The AquaFix 406 GPS weighs 12 ounces and measures 1.74 by 5.71 by 3.03 inches. It replaces the GyPSI 406 PLB, which weighs about 1 pound. The unit transmits a digitally coded 406 MHz distress signal using the international COSPAS-SARSAT satellite system.

Aimed both at commercial mariners and recreational boaters, two models of AquaFix 406 GPS are available. The I, or Interface, version ($640) can be connected to an external GPS receiver; the I/O version ($740) has an internal GPS in addition to an external connection.

Adding GPS information to the beacon’s 406 MHz data signal speeds up the search process. “It reduces what the searchers call the ‘notification period,’ and it reduces the search zone,” says Wahler. If no GPS data is available, rescuers measure Doppler shift using LEOSAR satellites to determine the beacon’s position, which adds 45 minutes to the notification period, he says.

Wahler says using an interface with on-board GPS is the fastest method because GPS data is being downloaded at all times, whereas an integral GPS has to acquire satellite signals before transmitting.

As most boaters know, the government is phasing out 121.5 MHz emergency beacons in favor of 406 MHz units. The 406 MHz frequency sends a UIN,

or unique identifying number, to the COSPAS-SARSAT satellite system. The UIN is linked to a database of information when the beacon is registered by the owner ( The database contains such vital information as the name of a boat and its owner, key contacts, and telephone numbers.

The AquaFix 406 GPS also transmits on 121.5 MHz for search-and-rescue homing purposes.

AquaFix units are built using polycarbonate blended construction. The units float, can be attached to PFDs, and have a functional test for battery power, internal circuitry and 406 MHz transmission, according to the company.

ACR has been manufacturing PLBs and selling them in other countries for several years, Wahler says. Government approval is on a country-by-country basis, he says, and the FCC made PLBs available in the United States July 1, 2003.

A five-year study in Alaska showed the life-saving potential of PLBs in U.S. waters, Wahler says. “In that five years, just in Alaska, over 200 lives were saved because of the use of personal beacons,” he says.

ACR Electronics Inc., Fort Lauderdale, Fla. Phone: (954) 981-3333.