It has to be said that not an awful lot of *different* things happen. Sometimes the same things happen often, but it fits in very well with the characters and their personalities. A flick through will fail to impress you, but immerse yourself in it and you will be rewarded. And hooked. I'm up to 'The Reverse of the Medal', and I'm not remotely bored of any repetition.
Oh really you must try it, it's just superb. I only started reading after having seen the film, and normally I'm just like you, but here for once is a film that does justice to the book but where the books are so much more. Also there is a strong story-line that carries you through all the books - and not all of them are 100% set at sea - so really they're well worth a read.
I've heard quite a few people rave about the Aubrey / Maturin series, and I'm tempted to pick up "master and commander" just to see what all the fuss is about
The only two things putting me off are that I *really* dont like reading a book after watching the "film of", and secondly I'm a bit dubious that a series set on a ship (same ship?) can sustain itself for 20 books - I mean how many *different* things can really happen?