Members of the Tynemouth Volunteer Life Brigade had to be lowered down the cliffs at Tynemouth Priory to reach the 17-year-old in the early hours.
They helped transfer him to a rescue helicopter from RAF Boulmer.
When it was over, it was found that two cars parked nearby and belonging to brigade members had been scratched.
The brigade described the actions as "extremely disappointing".
The Cullercoasts RNLI inshore lifeboat was also involved in the operation, with two crew members swimming to the rocks and administering first aid.
He was suffering from what is thought to be hypothermia and was airlifted to hospital where his condition is said to be poorly but stable.
Volunteers rescuing a teenager found unconscious on rocks on the North Tyneside coast had their cars damaged by vandals.