1972 disaster movie
from Irwin Allen
(who was not credited for some reason) about a cruise ship struck by a tidal wave
and flipped upside down.
A group of survivors, including Ernest Borgnine, Red Buttons, Shelly Winters and Roddy McDowall, and led by Gene Hackman try desperately to stay alive and escape from the sinking death trap.
One of the best disaster movies of all time. Certainly more interesting than Titanic, though obviously much more fantastic. A really bad sequel was made starring Michael Caine.