Cutthroat Island (1995) on Netflix

Morgan Adams' father's dying gifts to her are his pirate ship and a one-third part of a map of a treasure island - unusually inscribed on his scalp. Thinking herself in need of a Latin scholar to unravel the map, she buys learned slave William Shaw and sets off in search of the rest of the map. However, it is Shaw, obviously with plans of his own, who gets the second part. He's somewhat easier to deal with, though, than the holder of the last part - Morgan's less-than-loving piratical uncle Dawg.