The Coast Guard called off its search for Robert Gilsey, 55, at 12:15 p.m. today.

Gilsey’s 23-foot boat, Ripple, was discovered around noon on Tuesday off Richmond Island, about one mile south of Cape Elizabeth, with the keys in the ignition and the throttle at the on position with no fuel, said Ensign Ben Crowell of the Coast Guard.

Gilsey was not on board. He was last seen leaving Portland harbor on Monday night at 7:30 p.m. Crowell said some activity came from Gilsey’s cell phone around 12:30 a.m. Tuesday.

Crowell said it appeared that Gilsey was attempting to repair something on the boat’s engine when he must have fallen into the water. Upon discovering Gilsey’s boat, search and rescue teams that included the Maine Marine Patrol, Cape Elizabeth WETeam, the Portland Harbor Master and the Falmouth Harbor Master.

Coast guard resources used for the search included Station South Portland, a falcon jet from Air Station Cape Cod, 110-foot cutter Grand Isle and the 175-foot cutter Marcus Hanna.

Crowell said that Gilsey lived on his boat at Diamond Cove Marina on Great Diamond Island where he was employed.

The Maine Marine Patrol is continuing its search throughout the day.

Anyone with information regarding Gilsey is asked to call the marine patrol at 657-3030.