BBC's Bob Sinkinson: The warship received reports of someone clinging to debris

The woman who had been swept 50 miles out into the Caribbean was picked up by a Lynx helicopter from HMS Sheffield, helping with the relief effort in Honduras.

Speaking from HMS Sheffield, Lieutenant Commander Mark Folwell said that his crew were amazed to discover that the woman had stayed alive for so long.

"It is quite remarkable that she survived after all this time out at sea by herself in the elements," he said.

"It is quite a feat of her own mental strength, her stamina and physical courage."

Lieutenant Commander Mark Folwell: "She was washed out to sea by flood water"

The woman was spotted by a US coastguard who alerted the Sheffield.

She is now receiving medical treatment on board the ship.

A Ministry of Defence spokesman said: "She is drifting in and out of consciousness but she is alive and stable.

"The ship and the helicopter are continuing to search in case there are other survivors, but there was nobody else with her."

Flooding in Honduras has left thousands stranded

HMS Sheffield, which had been on a drugs-fighting operations in the Caribbean, has been helping disaster relief efforts since Friday.

Yacht still missing

Initially it was thought that the woman was a survivor from the yacht Fantome, missing in the hurricane.

The luxurious four-masted vessel is skippered by British-born captain Guyan March, 32, from St Austell, in Cornwall.

The UK Foreign Office confirmed that one Briton was among the 31 crew who are missing, but refused to confirm or deny his identity.

The 282ft vessel was on a tourist cruise near Belize and the Bay Islands early last week.

US coastguards say they have not given up hope of finding the crew alive.