A middle-aged man drowned and another was seriously injured when they jumped into the sea off a pier in Essex, in a stunt known as "tombstoning".
Five men jumped off Clacton Pier in Essex
The two men - both believed to be in their 40s - were found face-down in the sea by lifeboat crews after jumping off a pier at Clacton, Essex, on Saturday.
Emergency services were alerted at about 1830 BST when five men, fully clothed, reportedly leapt in.
Police said they were not treating the incident as suspicious.
But police added they were preparing a report for a coroner.
"The report was of five middle-aged men jumping off Clacton Pier into the sea," said a spokesman for the Maritime and Coastguard Agency.
"Two men were reported to be unconscious in the water."
'Not getting message'
The pair were flown to hospital. One died and the other is now in intensive care.
Tombstoning - the practice of jumping off cliffs, piers, harbour walls or other high points into the sea - has claimed a number of lives across the UK in recent years.
Father-of-six Delwyn Jones, 46, of Merthyr Tydfil, Mid Glamorgan, died in June
after leaping 30ft into the sea at low tide near Torbay, Devon and two years ago a man died after flinging himself from cliffs in Torquay.
A 14-year-old girl injured her spine last month when she jumped 30ft (9.14m) from cliffs onto rocks in Paignton, Devon.
Duty watch manager for Thames Coastguard, Anthony Mayhew, said: "Once again, we see another fatality sustained by jumping from cliffs or structures into water.
"People of all ages are still not getting the message.
"Jumping from any cliff or structure into water is dangerous. It could result in serious injury or death."