Murder on the High Seas

A gold-digging woman wins a big settlement against an older married man, which threatens to destroy the man's family. His son, discovering that the woman is part of a ring of blackmailers and that she is planning to flee the country, takes along his hulking chauffeur and follows her onto an ocean liner. There the two pretend to be a pair of wealthy playboys so that the woman will make a play for him and try to blackmail him, too, so he can then expose her and prove his father's innocence. (imdb)