Ian Reynolds was swimming to the mainland

Ian Reynolds, 29, an outdoor pursuits instructor, was swept away by the tide in a dangerous stretch of water off Gower.

He was trying to cross a flooded causeway to the mainland from the Worm's Head, a small island where he was camping with a female friend.

South Wales Police have appealed for anyone who saw him to come forward.

Mr Reynolds has not been seen since 0730 BST on Friday and police said on Saturday they were growing more and more concerned for his safety.

Air and sea rescue teams searched the waters and beaches along the Gower coastline on Friday and Saturday.

Mr Reynolds is 5ft 6ins tall with light brown hair, and had pierced ears, eyebrows, and tongue. He has tattoos on both arms.

At the time of his disappearance, he was wearing a black fleece, khaki trousers, and grey walking shoes.

Air and sea search teams worked on Friday and Saturday to try and find him. The search was called off on Saturday afternoon.

Mr Reynolds and his companion - both of whom worked part-time at Swansea College - had planned to leave the island at 0530 BST, but overslept.

Walkers helped search the area on Saturday

The four-hour tide "window" recommended to cross the causeway between Worm's Head and Rhossili in safety ended at 0610 BST on Friday.

As they made their way across the causeway towards the mainland, they got caught up in strong currents.

Both were carrying camping gear at the time. The woman held on to hers and used it as a buoyancy aid, but Mr Reynolds let go of his.

A spokeswoman for the coastguard said: "They tried to cross the causeway, but the causeway was flooded. She made it across but could hear him shout cries of help".

The woman was treated in hospital for hypothermia and was described by police as being in "an extremely distressed state".

South Wales police have appealed for anyone who may have seen Mr Reynolds to contact them.

Heard screams

The alarm was raised at 0816 BST after the woman struggled ashore alone and reached an emergency phone.

Coastguards have described the stretch of water as a particularly dangerous one. Steve Jones, one of the first to respond to the call, said he and his colleagues heard Mr Reynolds' cries, but no-one could see where he was.

"We were there within three minutes of the call-out," he explained. "We could hear him screaming, for help. There were eight of us here, but not one of us could see him in the water. It was very distressing."

Emergency crews were hoping Mr Reynolds had used his survival training to bring himself ashore at the one of the many isolated beaches on the Gower Peninsula.

A spokeswoman for Swansea College said the two part-time members of staff were on an independent camping trip, but the college was helping with the search.