One man has died and another was taken to hospital after their dinghy capsized at sea.
The two men, aged 71 and 73, were rescued from the water on Monday afternoon, Thames Coastguard said.
Several members of the public called the coastguard after spotting the pair in trouble.
A rescue team from the Southend RNLI discovered one man clinging to the boat 300 yards off the coast of Thorpe Bay, Southend, while the other had begun to drift away in the current.
The pair were found near the Thorpe Bay yacht club.
It is unclear why the dinghy capsized, although it is thought they may have been attempting to board a moored boat.
Both men received medical attention on the shore for up to an hour but the 73-year-old died at the scene. The second man is understood to have been taken to Southend University Hospital.
A Thames Coastguard spokesman said the two men may have been heading towards a boat on the mooring.
He said: "We cannot speculate on the cause of death at this time."