This isn't just a fun romp through the ocean searching for your boats, it's also a historical project that communicates a lot of information about what it was like to be a pirate at this time. The players are playing real pirates in real relationships doing real piratey things. The question is, do the players realize this? I'm assuming that I'm talking to the Game Master here, as they would be the one with all of the facts. How do you engage your players in the history of this module? How do you get them to think historically?
I've made up some surveys that you can give your players before and after playing. The Game Master Handbook also has some hints and tricks for how to engage the players in the middle of the game.