Anne of the Indies (1951)

LaRochelle, a former pirate captain, is caught by the British. To get his ship back, he works as a spy against other pirates, first of all Blackbeard and Providence. He works on some ships, crossing the Caribbean sea, with the intention of being enchained, when a pirate ship is in sight, to make them believe he's an enemy of the British. One day, his ship is conquered by Captain Providence. What nobody knew before, Providence is a (beautiful, of course) woman. She believes his story and so he joins her crew. But Blackbeard, her fatherly friend, doesn't believe him. Providence and LaRochelle fall in love, although he is married. When LaRochelle tries to deliver her to the British, she forebodes the trap, kidnaps his wife and escapes. As for revenge, she wants to sell his wife on a slave-market. LaRochell gets his ship and his crew back and follows her. ...