Having read the book and then watched the movie, it’s amazing how much technical detail you don’t even get to approach in the film. This is just the nature of the medium, but the book is very focused on the captain’s inner thoughts and technical descriptions, awareness of limitations, and homages to the mental math involved. Highly recommend the book if you at all appreciated the movie.
I just looked and it looks like there are two books by Forester. One is The Good Shepherd which is the original book and the other is Greyhound which is also by Forester and is sold as the movie tie-in. They have different number of pages, so I assume they are different.
Edit: I ended up buying The Good Shepherd because it was only $0.99 for the ebook.
