The Coastguard pulled a 16-year-old girl up a 100ft cliff at Castlerock - only moments before large breakers overwhelmed the position she had been standing in.
Coleraine station officer in charge, Chris Lyttle, told this newspaper that four children had been walking along the north coast last night when a rapid spring tide came in.
Two boys and one 16-year-old girl managed to swim to safety but the third girl was trapped on the rocks, 300 yards west of Castlerock Beach.
The alarm was initially raised some time after 6pm.
“It was a position she could not escape from,” Chris said. “She was suffering from hypothermia and exhaustion and had also swallowed a significant amount of sea water.”
As a result she was unable to swim the short distance off the rocks to an in-shore coastguard vessel.
The only alternative was to lift her up the cliff by rope.
“A Coastguard rope technician was lowered down 100ft and lifted her just as large waves broke over her position,” he said. “It was very choppy.”
The girl was reunited at the cliff top with her “very happy” parents, he said.
Both girls were taken to hospital as a precaution as they had both swallowed a significant amount of sea water; there was a risk of secondary drowning later if it was still in their lungs.
They were both from the Ballymoney area, he said.
“The important safety message is that it may seem inviting to cross rocks at the beach but you can quickly become cut off,” he said. “If so you should dial 999 right away.”
An eye witness said: “She walked the last few yards at the top of the cliff and you could see her wrapped up in the aluminium foil.”
Family members rushed to be with her as she made it to the top, he said.