"We have been told they had a handheld radio and an emergency position-indicating radio beacon
but there has been no signal from either of them.
Fr O'Callaghan, from Ballycotton, said: "The night the Maggie B sank, the Epirb Emergency Position Indicating Radio Beacon
was not working.
Mobile Tracker devices have long been one of the most effective ways of recovering stolen cars and if a thief knows that a car he has taken is likely to located by a built-in radio beacon
, then the chances are he'll move on and look elsewhere.
An automatic radio beacon
also alerted Securicor's HQ that one of their crew was in trouble after the van hit the hole with such force that its rear doors burst open.
Proposed experiments include a radio beacon
orbiting the planet Mercury to detect changes in the gravitational constant, another space-based facility to detect gravitational radiation and a test to study Einstein's general theory of relativity to an accuracy of 1 part in 1 quintillion (10.sup.18).
The range of the 5-watt handhelds, of course, limits effectiveness; in a high-seas abandon-ship scenario nothing beats an Emergency Position Indicating Radio Beacon
, or EPIRB, whose signal is detectable by satellites.
The yacht owner and his wife, from Devon, had dumped their 18-year-old emergency position indicating radio beacon
(EPIRB) in a skip at Ardfern Yacht Centre in Argyll where their boat is moored.
Having already faced a 45ft freak wave, the crew's the Emergency Position Indicating Radio Beacon
was triggered by heavy seas which hit the craft while she was on sea anchor.
And just in case there really is big trouble, Spirit carries an emergency personal indicator radio beacon
. Once activated, a unique signal identifying the boat and its location to within one square mile, is transmitted to passing ships and aircraft.
The stranded mariners triggered their emergency position-indicating radio beacon
and the signal was picked up via satellite by staff at a rescue centre in the Azores.
In addition, the role of the lander as a fixed radio beacon
will allow a number of experiments in celestial mechanics, such as detailed measurements of the motions of Phobos relative to Mars.