The former paratrooper’s body “was found lifeless inside the cabin”, they said.

The avid triathlete set off from mainland Portugal’s southern tip on January 1, but there had been no contact with him since overnight Thursday to Friday when he activated two distress beacons.

It was just his latest adventure after crossing the Atlantic alone in a custom-built barrel in 2019, a 127-day trip followed by thousands on Facebook.

Savin was hoping again to reach the Caribbean, this time in a rowing boat eight metres long and 1.70 metres wide, with a rowing station at its centre.

His team earlier on Saturday said they were “very worried”.

“We haven’t heard from him since 00:34 yesterday (Friday) morning,” they said, adding that he had activated “two distress beacons, telling us he was ‘in great difficulty’.”

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His daughter in a Facebook post said a search operation “was immediately set in motion in coordination with the French, Portuguese and US sea rescue services”.

He was last heard of north of Madeira, Portuguese islands off the northwest coast of Africa, on his way to Ponta Delgada in the Azores.

Soon after leaving on January 1, unfavourable wind conditions had forced the adventurer to extend his trip by 900 km (550 miles).

On Wednesday, Savin had reported “strong swell and … wind” on Facebook, adding that he had been forced to switch from using an electric water desalinator to a backup one operated by hand.

“It’s costing me physical energy,” he wrote.

But “be assured, I am not in danger”.

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Savin, who said rowing across the Atlantic was a way to “laugh at old age”, celebrated his 75th birthday on Friday last week on board his two-cabin boat.

He left with it packed with 300 kilos (660 pounds) of equipment, including freeze-dried food, a spear gun to fish and a heater, as well as the two desalinators.

To celebrate his birthday, he had also brought along his mandolin, foie gras and champagne.

“I’m off on holiday to the open sea,” he had said before leaving.

“I will row eight hours a day and when the wind blows too hard, I’ll close myself in,” he said.

Savin was looking forward to an extra safety measure that he did not have during his last barrel crossing: a tracker to make him visible to the radars of passing cargo ships.

After returning from his last trip, he had written a book to recount his journey.

The following year, when the coronavirus pandemic hit, he gave advice to fellow Frenchmen on how to avoid cabin fever during confinement.

“Everyone needs to embrace their passion … Start drawing, learn to play the harmonica, if it does not bother the neighbours,” Savin said.

He said he appreciated the solitude of his 2019 trip, adrift in a barrel on the ocean.

“I wrote my journal, I read a lot, I exercised,” he said.

Through a porthole in the floor, he was able to admire passing schools of fish. And sometimes, he spotted dolphins.