On New Year's Eve, the luxury ocean liner Poseidon is on a magnificent voyage from New York to Athens, Greece. Unfortunately, disaster befalls passengers and crew when the cruise ship is capsized by a huge tidal wave brought on by a submarine-induced earthquake. Though the casualties are many, 10 passengers survive to make a harrowing journey up to the overturned ship's bottom where they try and escape to safety. The ensemble cast includes Gene Hackman, Ernest Borgnine, Shelley Winters, Roddy McDowall, and Red Buttons.