Coastguards have warned about the dangers of "tombstoning" after a 75-year-old man jumped from an 80ft beauty spot and was seriously hurt.
The man is believed to have jumped from Durdle Door, Dorset, in the past but on Sunday he landed badly and needed to be rescued.
The swimmer, thought to be from Dorset, was in shock suffering severe abdominal pains and had to be airlifted to Dorset County Hospital, in Dorchester, for treatment.
Coastguards warned people about the dangers of the craze, which involves people jumping from heights into water.
A spokesman said: "What was being done here was tombstoning, jumping from rocks.
"It's dangerous. You don't know the depth of the water. So many people have been hurt in the past from tombstoning."
The pensioner was understood to be diving into the sea from the Jurassic Coast World Heritage landmark with other members of his family.
James Weld, of the Lulworth Estate which owns the beauty spot, said people continue to take part in the dangerous activity despite the vast array of signs warning people not to climb the cliffs.
"It's actually a very, very stupid thing to do because there are a lot of rocks under the water, which we and the coastguards try to tell people frequently," he said.
"To find somebody of 75 doing it, I just find completely unbelievable."