Members of Coleraine Coastguard assisted the Police and the Ambulance Service at the East Strand in Portrush on Saturday evening.
They were tasked following reports of an unconscious teenager.
After a brief search, in heavy rain, the casualty was located about 300m into the dunes.
He was given immediate first aid and transferred on a Coastguard stretcher to a waiting NIAS ambulance.
PIC: Coleraine Coastguard