The RNLI has urged people not to jump unsupervised

The activity of tombstoning has claimed many lives in recent years, but an outdoor pursuits organisation says its activity is safely supervised.

The International Coasteering Association says safety is its main consideration.

"People wanting to experience this should do it in controlled conditions," said operations manager Paul Bradford.

Otherwise, he said, "tombstoning is the pastime of drunken idiots".

Jumping was carried out by his organisation only in areas where the waters had been thoroughly checked for rocks or other obstructions and the jumpers were supervised by highly-trained, qualified instructors, he said.

"Jumping into water from heights is only one tiny aspect of our work," he added.

'Serious situation'

Other activities included cave exploration, rock climbing and traversing coastlines, Mr Bradford added.

The RNLI has campaigned against the tombstoning craze.

But Falmouth Coastguard Watch Manager James Instance said people had been leaping from cliffs into the sea for generations.

It was basically a safe activity, he said, as long as it was not from excessive heights and the water depths and hazards, such as rocks and tides, were known.

"We don't condone it," he said, "but we have no criticism if it's done in a controlled, sensible manner."

Steve Wills, from the RNLI said there had been at least five deaths from tombstoning.

"Compare this with research from the Royal Society for the Prevention of Accidents (RoSPA), which details only seven deaths from tombstoning over a six-year period (1997-2003), and we have a serious situation on our hands.

"Our advice applies to everyone - young, old, male and female - don't do it.

"Jumping from a height into water can kill. I urge people to think of the consequences of their actions.

"Young adults and teenagers can be easily impressionable and there have been reports of websites displaying tombstoning videos and incidents involving older men jumping into the sea - I'm concerned that young people may try to copy what they see."