Adding a few curses could add a whole new challenge for players.
For instance, take the curse of the black pearl. It could be, during the day, the ship is in tatters, always taking on a little bit of water (no more than the storm brings) and the players are at half health.
But, at night, the ship takes on a cool, special design and stops taking on water, the players take on a skeleton appearance (like a skeleton boss with their bought clothing) and gain extra health.
This is just a concept to show how the idea of curses (something common in pirate lore) could be implemented in a pretty typical RPG style. There could be all kinds of curses, though, with their own buffs and debuffs. There could be specific ways to get these curses and to break them.
I think it'd add a cool new aspect in all kinds of ways. Getting these curses can spur a crew to go on an epic voyage to try to free themselves from it. Coming across a cursed ship and trying to fight to get away from it, or even beat it could also be really cool.
