Crystalstone (1988)

Deserted by their father and with their mother dead, nine-year-old Pablo and his little sister Maria refuse to be separated from each other by their caretaker aunt. With a cross as their guide, they embark on a perilous, but ultimately rewarding adventure in search of a mystical gem that holds the key to happiness. They escape the fearsome metal hook of a pirate and are helped by a delightfully drunken Captain in their quest for the magic stone.