A flare goes up. A voice crackles over a radio: boat in distress.
U.S. Coast Guard rescuers respond. They have to.Most calls are legitimate - a pleasure boat with engine trouble, a sailboat taking on water, a fishing boat in flames.
But sometimes Coast Guard rescuers brave rough seas only to find the call was a hoax.
The financial and human toll from false alarms and hoaxes is a heavy one. Last November the Coast Guard spent almost $500,000 responding to one false alarm call of a charter fishing boat sinking off the coast of southern Oregon with 11 people aboard.
The calls cost lives as well.
In 1990, a father and son drowned when their fishing boat, the Sol E. Mar, sank off the Massachusetts coast. Coast Guard officials received a false mayday call at the same time the fisherman called for help.
The calls sounded similar. Coast Guard rescuers responded to the location given by the hoaxer. By the time they realized it was a fake and began searching for the father and son, it was too late.
"Our job is to save lives," said Mike Stone, spokesman for the Coast Guard office in Portland. "While we're spending time on one case that turns out to be a hoax, there could be another call that's real that we can't get to."
Fake distress calls are such a problem in the Northeast that Coast Guard officials are putting out radio announcements warning hoaxers they're breaking the law, said Glenn Rosenholm, a Coast Guard spokesman in Boston.
Rosenholm has seen a steady increase in the number of prank distress calls in last several years. Last year his office received 417 hoax distress calls, he said.