The youths, both aged 17, had been climbing and shortly before 4 pm had reached a point of no return in which they could neither get to the top nor go back down.
Realising their predicament in an area where there were loose rocks, they used a mobile phone to contact the Fire Service.
While they waited to be rescued they maintained contact with fire officers by phone and were spotted by climbing instructor Marcus Hill, who was at the bottom of Portelet Common taking photographs of sea birds.
