See below for pictures of three survival at sea books that I posted about. I've read two of them completely now and skipped ahead to the end on the third book.
First of all, the fact that these are true account type books ruins the suspense. You know that these people will get rescued eventually or arrive safely on land. So you read a day by day account of thirst, hunger and increasing weakness and encounters with storms and so on, but after about half a book's worth of that, you want to skip ahead to the last chapter.
But secondly, and this is a valuable lesson for anyone who finds themselves lost. In all three of these books, there was at least one person who had some sense of navigation and where they were and where they wanted to head. They were not aimlessly drifting. They tried to control their progress, so that even if they couldn't steer their rafts, they put out a sea anchor when the wind was blowing the wrong way. But more importantly perhaps, having some idea of where they were gave them an important morale boost because they all had hopes of arriving somewhere at some point so that their situation wouldn't seem hopeless. And when they did have some food and water, they knew how long it would have to last. Lacking a goal, their survival would have been much less likely.