A sea search has been stood down after reports of a possible missing diver.
A helicopter, plane, coastguard rescue teams, a lifeboat and North Wales Police all took part in the operation off Porth Ysgaden, on the Llŷn peninsula in Gwynedd after the alarm was raised at 13:15 GMT on Thursday, said HM Coastguard.
The search was ended at just after midnight with no-one found, the Maritime and Coastguard Agency said early on Friday.
Police said their officers were continuing to help with searches on land and their inquiries were ongoing.