Lewis Adrian Vowles, of Maulscombe, Brighton was on a fishing expedition with his father, John, and his friends, Kevin Gardner, 32, and Steve Buck, 19, when the tragedy occurred.

He had been visiting Mr Vowles for a holiday and was using his new fishing rod, a Christmas present, for the first time.

The survivors are recovering in hospital from the effects of hypothermia after they spent as many as three hours in the water.

Speaking from his hospital bed, Mr Vowles said the trio of men tried in vain to save his son's life.

He said his son had fallen unconscious before they were pulled from the water.

"We did everything we could," he said. "I hugged him and cuddled him and we took it in turns to lift him clear of the water."

The boy's grandfather, Harry Vowles said: "Lewis had been looking forward to (the trip) all over Christmas. He could talk of nothing else."

Hole appeared

The emergency began when a hole appeared in the 16ft vessel as it lay at least two miles offshore in the Bristol Channel between Penarth and Newport.

The group pulled on lifejackets and blew whistles to raise the alarm but did not have enough time to fire an emergency flare before the boat sank.

A crewman on the bulk carrier ship Astria, which was waiting in the area to pick up a harbour pilot, eventually heard the cries for help hours later.

An inshore lifeboat was immediately launched to rescue the four, who were then winched aboard an RAF search-and-rescue helicopter.

Lewis was pronounced dead at Cardiff Royal Infirmary.