As Argonor said, if you know LotR or LotOW, then the rules are nearly self-explanatory. It's a continuation of that same system.
It is a beautiful looking book. Full-color and new artwork throughout, lavish miniature illustrations (with figures painted and provided by many of the fine people here). There are great sections on history of the Golden Age of the Atlantic pirates, and stats for the big name pirates as well.
Tim lavished attention on the rulebook and the content shines as a result. If you knew nothing about pirates, you would come away with a good introduction to the real history and plenty of ideas on how to play.
I am glad to own it. I own enough pirates that I could easily cobble together a few crews, and if I want to run a 20-some model skirmish, I could easily imagine going to this book for the rules.