MONROE TOWNSHIP, Mich. — The U.S. Coast Guard has announced a $3,500 reward for help in catching a man who’s made at least 20 fake “mayday” calls on a marine radio operating in the Monroe area.

The Coast Guard’s Cleveland office said the man began calling in 2010, making claims that his boat is sinking. The Coast Guard is posting 15 recordings to see if anyone recognizes the man’s voice.

Lt. Justin Westmiller in Detroit said the calls could cause a disaster by diverting rescuers from a real emergency.

He said the prank caller uses marine band radio VHF-FM Channel 16. It’s the international hailing and distress frequency.

Westmiller said the calls come from the Bolles Harbor area on Lake Erie in Monroe County’s Monroe Township.

The U.S. Coast Guard said anyone with tips about the fake mayday caller can call (800) 773-2587.