I still have fond memories of expecting an assassins creed game and getting a fantastic priate game instead. It's even equipped with authentic Sea Shanties, and epic naval battles involving swinging to other boats and climbing into the riggings.

You dive for treasures.

You build a fleet.

You destroy coastal fortifications and hunt down legendary pirates.

Oh and there is that Assassing stuff but surprisingly little of it. It's like they started making an Assassins Creed game but then got understandably totally sidetracked by how amazing it is to be a pirate.