A 75-year old adventurer has been found dead during an attempt to row across the Atlantic Ocean alone, his support team have said.

The Frenchman Jean-Jacques Savin had activated two distress signals overnight Thursday to Friday.

“Unfortunately, this time the ocean was stronger than our friend, who loved sailing and the sea so much,” a statement by his team on his Facebook page said.

On Friday Portuguese maritime officials found his overturned rowing boat off the coast of the Azores, an autonomous Portuguese archipelago in the North Atlantic.

The next day they sent down a diver to search it, who found the former paratrooper’s body “lifeless inside the cabin”.

The circumstances of his death are yet to be determined.

As soon as the distress signals were received, processes were “immediately implemented in coordination with the French, Portuguese and American sea relief services,” his daughter wrote on Facebook on Saturday.

“Of course we are very worried,” she said at the time.

The keen triathlete, who previously successfully floated across the Atlantic in a barrel, had on Wednesday written on Facebook that he was battling strong winds and problems with his solar power.

“It’s costing me physical energy,” he wrote, but reassured his followers he was “not in danger!”

Savin was hoping to reach the Caribbean in an eight metre-long rowing boat, that had a rowing station at its centre.