This trailer for the 1956 John Huston/Gregory Peck film version of Moby-Dick gives an awful lot away.
Maybe they were assuming most people had read the book?
I haven’t seen it yet, but the New York Times liked it quite a bit.
A Thinking Reed
"Man is but a reed, the most feeble thing in nature, but he is a thinking reed" – Blaise Pascal
A Thinking Reed 
Oh, it’s a good film! You’ll like it, I think….
The screenplay was written by Ray Bradbury. Great movie.