I recently finished the penultimate Crichton novel, Pirate Latitudes. His last novel is still in editing and is rumored to be a techno-thriller, for which he is best known. But Dr. Crichton could write a mean historical tale of adventure as well (Eaters of the Dead being the other one I'm thinking of).
As I understand it, an assistant found a copy of this manuscript buried in one of his computers, finished but forgotten. The publishing industry being what it is, they grabbed it up and printed a million copies! I'm not sure why this would have been locked away, but I suspect he wasn't done with it. It was a rougher read. Crichton tells a good story, Jurassic Park, Andromeda Strain. Science gone awry with a small group of people trying to survive. In PL, Crichton tells of a 17th century pirate. Affected voice, more exposition than usual, jumpy narrative. That sort of thing. It was Fine. No Treasure Island or anything, but I enjoyed it alright.
Immediately after, I started in on my next read, the Last Raider by Douglas Reeman, also a tale of Naval Hijinks. Not to take anything from an obviously great man and writer, but there is sure a notable difference between someone writing about something they have experienced (Reeman was a sailor in WW2) and someone writing about something who hasn't.