Note: spoilers follow...
I heard it described as a long pause between two battles, and, on some level, that's true. But once you look beyond the superficial, the movie told one of many tales in the lives of the crew of the HMS Surprise and the man who led them - Capt. "Lucky" Jack Aubrey (Russell Crowe) - one which happened to begin with a defeat and end with a victory.
I found it to be genuine for a number of reasons, but chiefly for the performances - all of them - and the dialogue behind them. No scenes exemplified this better than those in the officers' mess, with the freely flowing drink and rousing a cappella verse.
Did you notice how they waited 'til the very end to show the French? Interesting device: showing the view from their ship without ever showing the men themselves. It gave weight to the phantom ship theme, now that I think about it. Hey, I'll admit it: some of those stories had me creeped out.
