Yacht search called off

Coastguards have carried out an intensive search

Coastguards have called off their search for four people missing since their yacht disappeared in the North Sea on Friday.

Thames Coastguard said the aircraft involved in the search had now returned to base.

Did the Tuila hit a cargo ship?

Worsening conditions in the North Sea have hampered the efforts of rescuers searching for the three students and a sailor.

The Tuila left The Netherlands for Harwich in Essex last Tuesday, but went missing three days later.

Students Chris McMenemy, James Chew and Carol Smith, all from Cambridge University, were on board when it went missing, as was skipper Adam Clackson, an experienced sailor in his 50s.

Thames Coastguard district controller Ian Jackson said: "This search has been one of the most intensive ever carried out in this area.

"Over the period from Sunday 30 July to today we have utilised seven lifeboats, a helicopter and five fixed wing aircraft.

Carol Smith: Her mother is urging people to keep looking

"I would be delighted if I was proved wrong and the boat turned up tomorrow, but unless there is anything positive there will not be any further action."

Francis McMenemy, Chris's father, told BBC Breakfast News he was disappointed the search had been called off.

He said: "You have got to remember we are talking about four extremely fit people. He [Chris] has a fantastic will to live."

The mother of Carol Smith, also called Carol, thanked the rescue teams for all their efforts.

She urged seafarers and the public to keep a lookout for signs of the Tuila.

"We're asking other people please to keep looking - if they can look in creeks and small ports in Britain and Holland," she said.

Debris recovered

Dutch coastguards recovered debris which looked similar to the red seat cushions fitted on the missing yacht, but the objects were not from the Tuila.

Similar objects were spotted by a motor boat crew on Saturday, but no link to the Tuila has been established.

Round-the-world yachtsman Tony Bullimore told BBC's Breakfast News that it was possible the yacht had been hit by a cargo ship.

He said: "If they had a very nasty collision it would have been minutes, or seconds, and they would have gone down."

This is one of the busiest shipping lanes in the world.. somebody should have seen them

HM Coastguard

Mr Jackson said he was "baffled" as to the missing yacht's whereabouts.

"This is one of the busiest shipping lanes in the world, with up to 400 ships a day transiting the area, in addition to 200 ferry crossings each day - and someone should have seen them."

The trip is believed to have been organised to build up sailing hours for the students, who are all members of Cambridge University's cruising club.