Producer William Goetz has supervised a remarkable job of making plausible the admittedly wild-eyed adventures of an odd assortment of moral derelicts who salvage a submarine with the intent of robbing the Queen Mary (hence the title) [based on the novel by Jack Finney].
Virna Lisi, Anthony Franciosa and Alf Kjellin, on the hunt for a sunken treasure ship off the Bahamas, hire Frank Sinatra and his partner, Errol John, who run a fishing boat business, to help them find the treasure. Sinatra, instead, finds a small sunken German submarine. Kjellin, a former German U-boat commander, talks the group into salvaging it and holding up the Queen Mary.
Only Kjellin is able to create a well-rounded character and is outstanding as the apparently bland German, holding in control his diabolic intent. Sinatra and Lisi are very good in roles that make few demands on their acting ability. John, while efficient in the tenser moments, seems inhibited in scenes where he must wax sentimental over his rehabilitation by Sinatra.