The Truth About Spring (1965)

Tommy Tyler (Sir John Mills), a lazy Caribbean sailor and his tomboy daughter, Spring (Hayley Mills), are out to search for a buried treasure. Tommy brings aboard William Ashton (James MacArthur), a young lawyer to help with the search. Ashton turns out to be handy when they encounter dangerous rivals. Tommy also tries to play match maker between Ashton and Spring-a difficult task indeed.