After Greer you have a few other people with lists of their own whose bidding you must do. You've still got a way to go, mate, before you get to board the Black Pearl and defeat the Goliath. But, be patient and enjoy the journey- sinking ships and building up your weapons is the fun part.
Boarding the Black Pearl and the "battle" with Goliath is over in a flash, and when its over, its over, and there's no going back to it (at least not until they add more to the game, or until you work up another character).
