The search in North Inishowen for 59 year old Tony Griffiths from the Culmore area of Derry is entering its third day.
Mr Griffiths, who was last seen on Monday evening, had been camping on the Isle of Doagh, and was reported missing by his family on Tuesday.
The sea search involving the Lough Swilly Lifeboat, Greencastle coastguard and the Sligo 118 helicopter was stood down last evening due to weather conditions. It's due to resume at 11 o'clock this morning.
Gardaí have repeated their appeal for help in tracing Mr Griffith's whereabouts.
Anyone with information is asked to contact Buncrana Garda Station on 074 9320540, the Garda Confidential Line, 1800 666 111 or any Garda Station.