That was my other answer mcs. I think Frank is right with his answer. Two ships were used, Missouri & Alabama. I have not seen the film but I have been told that the ship is called Missouri, so that is the answer I am going with.
The Query line states that they are looking for the name of the ship upon which the film was set, not the names of the ship they used for filming so it has to be Missouri.
The question asks what was the REAL name of the ship used for the setting. It was NOT the Missouri . The answer is clear in trivia in imdb for the film.