Northern Ireland fisherman Gordon Duncan, a 43 married man from Windmill Heights in Enniskillen, disappeared on Monday while fishing in Upper Lough Erne, Co Fermanagh.
A full scale air and sea search was launched at daybreak but so far without success. A spokesman said they were still holding out hope that the missing man had managed to swim ashore.
Mr Duncan, an experienced angler, was thought to have been wearing a life jacket, although the discovery of one at his home has cast doubt on this.
Mr Duncan was last seen in his small dinghy near Bellanaleck Marina, but at around 3.15pm two visitors to the marina spotted the boat floating at Cleenish Island with no-one on board.
