The Stranger in the Lifeboat isn't my favorite book by Mitch Albom and I found the story a little strange. I loved Have a Little Faith though.
A wealthy man was hosting a party aboard his yacht when an explosion rips through the boat. Several people are rescued in a lifeboat and Benji writes in a notebook the events of the shipwrecked people. One man claims to be "The Lord" which begins people guessing about who he is. A year later an empty raft washes on to an island and the local chief inspector tries to solve the mystery of those who had been on the raft.