I thought it was pretty good. They did a lot of things really well, but definitely could have improved some areas. In particular, I didn't like the way they chopped it up - 8 minutes of show, 3 minutes of commercials (I timed it.) You just start getting back into the story and you're yanked out of it for the SAME commercials over and over again. I also agree that there were elements that they didn't have to include. The costuming was terrific, though - the pirates were nicely grimy.
And yeah, it looks like they just had one, maybe two boat interiors - the exterior long shots were all CGI.