A MAN who caused a lifeboat alert as he attempted to swim the River Dart at Dartmouth, has been condemned for the dangerous prank which could have cost him his life.

The man plunged into the river at Kingswear at around 6pm on Tuesday evening and eventually clambered out on the South Embankment opposite the Dartmouth harbour office after covering more than 400 yards across the treacherous river.

As coastguard officers tried to speak to him, he and a group of some six friends ran away.

Meanwhile the Dart Inshore Lifeboat had been launched and reached him while he was still 20 yards away from the embankment – but he refused any offers of help.

Lifeboat spokesman John Fenton warned against attempting such a prank: "The light was fading. If he had got cramp halfway across he would have gone under and nobody would have got to him.

"It is highly dangerous. He wasn't wearing a wet suit. There was a strong tide and the water was extremely cold."

The man, who was in his 20s and was being egged on by friends, was first spotted by Lloyd Turner, the helmsman on Dartmouth Lower Ferry who called the lifeboat station.

The lifeboat team were in the middle of a crew meeting and after getting permission from the coastguard they were in the water within minutes.

"He was a strong swimmer," said Mr Fenton. "We were very quick off the mark because everyone was standing around the boat but he was 20 yards from the embankment when we got there.

"There was a strong flood tide and the water doesn't get any colder than at this time of the year."

He said the lifeboat crew had come alongside him but he had refused any help and insisted on swimming the rest of the way to the embankment.

Rob Clements, operations manager at the Dart lifeboat station, said: "This really was a silly idea. This man had chosen to swim across the 400 yards of river also used by the passenger ferry. A swimmer's head in the water is tiny and almost impossible to see. I'd ask people not to repeat this man's actions."