This cruise is a charity gambling cruise to benefit the Flanders Hospital. Merrill (Gavin MacLeod) was the best man at Florence Flanders' (Celeste Holm) wedding. Florence's never-do-well brother, Frank Bannon (Richard Jaeckel), is addicted to gambling and owes ten thousand dollars to shady Al Dixon (Antony Ponzini). So Frank hires Dixon to run the gambling tables, to Florence's dismay. Newlyweds Nancy and Stewart Sidon (Leah Ayres and Shea Farrell) are considering moving in with his parents for a few years and saving some money before buying their own home and starting a family. But gambling fever gets the best of Nancy and she loses all their wedding check money at the tables. High school teacher Michael Borden (McLean Stevenson) owns an invaluable antique silver dollar, which he plans to sell to a collector in Acapulco, until his girlfriend Sally (Jo Ann Pflug) accidentally drops it into one of the slot machines and accidentally brings out the greedy beast in him.