A High Wind in Jamaica (1965)

The parents of children living in Jamaica, afraid that the kids are growing up uncivilized, decide to send them to England. But during the voyage, the childrens' ship is boarded by pirates and in the confusion the children wind up trapped on the pirate ship. The children view it as a lark, and one of them, a girl named Emily, develops an unusual bond with Chavez, the pirate captain. The superstitious pirates can't wait to unload the kids at the first port, but a tragedy prevents it, and Emily's relationship with Chavez takes a fateful twist.