When John Huston was casting for Moby Dick he got to make it on condition that he get a name actor to play Ahab. He went to Gregory Peck who was surprised by the offer. Given his image and the roles he had played up to that time, Peck thought he'd be better cast as Starbuck the first mate. Nevertheless he agreed to do Ahab.
Peck got mixed reviews at the time, but over the course of 50 years his performance has gotten better with time. The film itself which was shot in Ireland and Wales has also aged well. It's a nice depiction of life on a whaling ship in the 1840s and the crew of the Pequod are nicely cast in their roles.
Orson Welles was set to do his own adaption of Moby Dick and canceled his film when he heard his friend John Huston was doing Moby Dick. Welles asked about doing Ahab, but was given the small role of Father Mapple, the minister who blesses the Pequod's voyage. In fact Huston gave Welles a free hand to do the scene as he saw fit and the results are gratifying.
Of course Herman Melville's novel is about obsession and vengeance. I've always thought the point of Moby Dick is that the evil white whale who Ahab so personalizes and demonizes is just a whale doing his whale thing trying to stay alive. It is in fact the whalers who hunt him and his kind. And Ahab losing his leg is what we would call an occupational accident. The evil is how Ahab seduces the whole crew into his own madness, even first mate Starbuck, played winningly by Leo Genn who is the voice of reason and civilization.
Other cast members to note are Harry Andrews as second mate Stub, Friedrich Ledebuhr as Queequeg the Pacific Islander harpooner, and of course Richard Basehart as Ishmael who tells the tale.
