The Coast Guard has ended its active search for a 65-year-old Connecticut man who fell off his sailboat Monday near the northern entrance to the Sakonnet River.

Bernard Mochan, of Clinton, Conn., had been sailing with his wife on the 32-foot Elizabeth when the vessel’s boom hit him on the head and he fell overboard. He wasn’t wearing a flotation device.

That evening, searchers found a hat that Mochan’s wife said belonged to her husband in the waters about a tenth of a mile west of Tiverton. The Coast Guard had been searching for him since, but found no further signs.

“Ending a search is a very difficult decision,” Capt. Raymond Perry, commander of Sector Southeastern New England, said yesterday in a statement. “But we think it is highly unlikely that someone could survive more than 40 hours in the water without a life jacket on.”