Plot
Care-free streaming Charlie (Matthau), the gambler inside debt to his various bookmaker & loansharks, cons his widowman brother-around-law Herb (Lemmon) into an expenses-paid luxury cruise inside seek of rich, lonely ladies to fleece. A catch, which Charlie doesn't reveal to Herb until the ship has left port, is that it is needed to become dance hosts & come to sleep around a little cabin in the gut of the ship.

Ruled concluded by the tyrannic control-freak Sail Director ("a song and dance man raised on an army base") (Spiner), it wash their better, despite non existence actually respire to dance. It meet many ladies, including people on the lookout for rich men. These include a luscious Liz (Cannon) & lovely Vivian (Gloria DeHaven). Th guys use numerous mis-mishap on a ship & ashore, prior to it eventually leave the ship around pursuit of the ladies.