The Crimson Pirate (1952) on Netflix

After taking control on a British war ship Captain Vallo, the Crimson Pirate, sees a money-making opportunity. Aboard the British ship is Baron Jose Gruda who has been sent to the Caribbean to stop an independence movement led by someone named El Libre. Vallo's plan is to sell the ships store of guns and powder to El Libre and then double his money by telling Gruda who and where the rebel is to be found. Things don't go quite as planned after Vallo meets the beautiful Consuelo, who just happens to be El Libre's daughter. Vallo has a change of heart and fights with the rebels.