Two boys swept off cliffs by a wave are unlikely to be found alive, Dorset coastguards have admitted.
Charlie Morrell and Matthew Myburgh were both local boys
The search for Matthew Myburgh, 16, and Charlie Morrell, 15, has been handed to police and downgraded from rescue to search and recovery.
On Saturday, Dorset police were being helped by a specialist dive team from Avon and Somerset Police in the search.
A trainer has been found belonging to one of the boys, who disappeared into the sea at Lulworth Cove, on Thursday.
The trainer was found on the eastern side of the cove, the coastguard said.
A spokesman added "a successful outcome looks unlikely" as the operation was handed over to police.
The missing boys were with a third teenager who raised the alarm when he saw his friends washed into the sea.
Mark Rodaway, senior coastguard officer for the south of England, said: "Everything we had available to us has been brought to bear in this particularly awful incident.
"Overall we've had in excess of 100 people searching for the two boys.
"Given the awful weather conditions that both the boys and the rescue workers were facing, with the temperatures and the time we are now looking at, a successful outcome looks unlikely.
"We have covered certain areas. We are certain the boys are not there."
About 100 people have been involved in the search
Mr Rodaway said a trainer had been found that had been identified as belonging to Matthew.
He added strong winds and high seas had washed debris up on the beach but no other items belonging to the youngsters had yet been identified.
Ch Insp Nick Maton, of Dorset Police, said if the boys were not found over the weekend by underwater search units from Avon and Somerset, a private company specialising in underwater searches would be brought in on Monday.
Rescuers had scoured a 10-mile section of coast from Warbarrow Bay to Bat's Head.
The boys, from the local area, were fishing when they went missing in heavy rain and strong winds, where waves up to 9ft high battered the cove.
Ch Insp Maton said: "The storm was exceptional, people are already saying it was one of the worst storms in living memory."
Mr Rodaway said that with the water temperature at 14C, a person could survive for about three hours without wearing survival equipment.
Richard Holman, head teacher of The Purbeck School in Wareham, where the boys were pupils, said: "We are obviously concerned for their safety and well-being. I hope they are found alive and well."
Ch Insp Nick Maton said the youngsters' families had been waiting in a nearby hotel for news.
He said the boy who raised the alarm was "highly traumatised" by the incident.
He had gone into the water to try to help his friends.
James Weld, 40, who manages owners of the cover, the Lulworth estate, said: "It's a small community. They are local lads and it's a tragedy."