I read a great book back in the '80s called "Adrift", the story of Steven Callahan, who survived 76 days lost at sea. At the time, it was believed to have been the longest solo survival-at-sea.

https://en.wikipedia.org/wiki/Steven_Callahan

https://www.amazon.com/Adrift-Seventy-six-Days-Lost-Sea/dp/0...

Unlike the man in OP's story, Callahan was adrift in a small life raft and had only a tiny emergency kit aboard with which to save himself with. He used those meager supplies to perform some miracles, including a very clever technique that he came up with to patch his raft when it developed a leak.