The investigation continues into the false distress call claiming a yacht had exploded off the coast of Sandy Hook Monday.

Coast guard officials have now ruled it a hoax, saying it cost taxpayers thousands of dollars and hours of search and rescue efforts by land and sea.

In recordings released by the Coast Guard, the caller sounded calm and convincing.

“We’ve had an explosion on board and we’re taking on water…there are 21 people on board, three are deceased.”

But after a four-hour search by more than 200 agencies looking for the boat dubbed the “Blind Date,” Coast Guard crews found nothing.

“We did not see a sign of smoke, debris, any people in the water…and at that time we determined that it was a probable hoax” said Erik Swanson, Coast Guard Petty Officer in New York.

Officials said the false distress call likely came from a radio line in New Jersey or southern New York.

“Two line of bearings picked up an antenna that pointed over the lower bay of New York up into Staten Island and into New Jersey” said Coast Guard Deputy Commander Gregory Hitchen.

Its not uncommon. The Coast Guard said they responded to more than 60 suspected hoax calls in the region last year alone.

“This is an unusual case, however. We sometimes get hoax calls, but not of this scale and of this amount of detail.”

They’re offering a $3,000 reward for any information leading to the person responsible.

The Coast Guard is investigating a possible tie between Monday’s hoax and a mayday call around this time last year.

On June 14th, 2011, a caller using a radio channel reported that a 33-foot sailboat was taking on water near Sandy Hook. Less than an hour later, another call informed the Coast Guard that the boat was 90 percent submerged, and the caller claimed that four boaters were transferred to a small dinghy.

A 10-hour search costing almost $90,000 turned up no sign of the boaters.

“Right now we just really want to educate the public about the danger of these hoax calls…the danger they pose to the public, and our first responders” said Swanson.

Rescue officials say the search operation cost agencies including the State Police around $16,000 which includes the operating cost of one 50-foot vessel, four helicopters (including two medevac helicopters) and troopers to operate them and the Coast Guard more than $300,000.

Making a false call is a federal felony, with a maximum penalty of six years in prison, a $250,000 fine and reimbursement to the Coast Guard for the cost of performing the search.

(The Associated Press contributed to this report)