I loved this book when I was younger and revisiting it, I can see why. A memorable combat sequence around a sea mount really stuck with me. People who enjoy watching any sort of submarine movie because they're cool as hell will likely enjoy this book.
However.
While overall I enjoyed Crush Depth, it was a bit frustrating in parts. Most of the strategic narrative of the book is enemy captain Jan ter Horst playing 7D mind chess on a truly global scale, while Our Hero Jeffrey Fuller is so distracted by the celebrity of his opponent, relationship drama and a comically hardarse commanding officer that he behaves like an absolute trainee in critical moments. A crucial part of the endgame battle basically amounts to: Sonar: "Captain it's submarine" Fuller: "Go toward it immediately"... and yet guess who comes out on top. You will not be surprised. Insert a picture of an American flag here. I recognise there is an attempt to show Fuller developing as a commanding officer but honestly he deserved several torpedoes up the backside at multiple points in the book.
Fuller also absent-mindedly treats his girlfriend like garbage then whines when she dumps him, and I couldn't figure out if the author was conscious of it or not. As is unfortunately typical, men are judged on their ability, and women are judged on their looks - any ability they have is totally secondary. A shame.
Overall I would recommend Crush Depth as an easy read, especially if you're like me and haven't read any fiction in quite a long time and are trying to get back into the swing of it.