A French sailor survived after spending 16 hours in cold water under his capsized sailboat by breathing through a shrinking air bubble.
Laurent Camprubi, 62, ran into trouble about 8.30pm on Monday when his boat, the Jeanne Solo Sailor, was 22 kilometres from the Sisargas Islands off Spain's north-western Galicia region, Spain's maritime rescue service said.
After he fired a flare to show he was in difficulty, a rescue ship and three helicopters were immediately sent and the search team found the boat overturned in the darkness, the service said.
In a video shared by the service, a rescuer is lowered on to the ship's hull and bangs on it before listening for signs of life.
Mr Camprubi began knocking from inside and crying out for help but because of the rough seas, the rescuers had to first prevent the ship from sinking further and waited until morning to get him to safety.
"I knew they were there but I had to hold on," he told AFP. "I thought of my wife, my children. I told myself that I would hold on for them. I could not abandon them.
"When I heard the diver it was a great relief but then there was a whole operation that took time because conditions were difficult."
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Spain's maritime rescue service described the operation to save Mr Camprubi as "verging on the impossible".
First rescuers attached buoys to the capsized ship's hull, and the next day two divers equipped with torches swam under the boat to look for him, the coastguard said.
When the divers saw him they passed a pole towards him, which he immediately grabbed.
"He rushed towards us … we pulled him to the surface," the coastguard said.
Once he got to the surface, Mr Camprubi said he hugged his rescuers before he was flown to hospital by helicopter for checks.
"These are moments which I will never forget," he said.
Although Mr Camprubi's body temperature was just 34.5ºC when he was rescued and he was very dehydrated, he escaped uninjured.
He said his boat capsized in just a few seconds and then began to sink.
"The water continued to come in little by little and the electronic equipment of the ship tore off," Mr Camprubi said.
"It was getting more and more dangerous to move around so I crouched down in a corner and waited, hoping for help to arrive."
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Mr Camprubi, an experienced sailor who has won several regattas, said at first he had an air bubble of about 80 centimetres that allowed him to breathe but "this space was slowly shrinking".
"I understood that my hours were numbered," he said.
The maritime rescue service said that when Mr Camprubi was brought to the surface about noon on Tuesday, he had "just 30cm of air". It said he had spent 16 hours under the boat.
Juan Ferrer, head of the rescue operations, said the neoprene suit Mr Camprubi was wearing prevented him from getting hypothermia.
He also praised the French sailor for "calmly awaiting our arrival".
Mr Camprubi, who had set sail from the Portuguese capital Lisbon on Sunday morning, said he expected to be reunited on Thursday in Spain with his wife and children.
"I am going to continue to sail," he said.