Coastguards have issued a warning against "tombstoning" after a man aged 22 got into difficulty doing back-flips into the sea at an East Sussex harbour.
The man was swept away by the current before being spotted by the skipper of a local dive boat off Newhaven, who hauled him on board semi-conscious.
Coastguards, who were alerted at 1005 BST, sent the Newhaven lifeboat to take him to the lifeboat station.
The man was taken to hospital in Brighton but released later.
Solent Coastguard said the man was in the water for 20 minutes before being rescued.
Repeated warnings about the practice of "tombstoning" - leaping into the water from a height - have been issued.
Former soldier Sonny Wells, 20, was paralysed after jumping from South Parade Pier, Southsea in Hampshire in May.