help has been looking for long time

hey hey looking for an old movie like 1940-1990. what I can remember. a man come to an island and the first he meets are two sisters who bathe naked. he’s looking for a gold or something. and at some point. he takes home but with only one of sister and the other try to swim after as they leave island in an old ship. and thinks he slept with both of them but fell for the eldest