I rate Patrick Robinson's stuff quite highly, it's best read in the right order though. Nimitz Class is good, but with less submarine content. Kilo Class and HMS Unseen are great, Seawolf and The Shark Mutiny weren't my favourites but they're still pretty good.
Scroll down to the 'Series' bit on this page and you can get a bit of info on them:
http://www.fantasticfiction.co.uk/r/patrick-robinson/