Red October (fictional submarine) not feature. Also the bridge tower of the submarine is taller and more simplified, with no large bulging lower section of a standard Typhoon bridge tower, but instead a much smaller bulge. The difference in appearance of the bridge tower may have been an error in the design of the model of "Red October" as earlier on in the film, schematics of a Typhoon-class submarine are shown which display a standard Typhoon bridge tower but also carry the sonar array attached to the rudder as on "Red October". "Red October" is also longer due to additional ballistic missile launch tubes.
The Hunt for Red October are many deviations, including "Red October" traveling up the Penobscot River in Maine to dry dock, and the "caterpillar drive" being described as a magnetohydrodynamic drive system, essentially, "a jet engine for the water". The film received mainly positive reviews from critics, holding an 87% rating from Rotten Tomatoes based on 66 reviews. It was the 6th top-grossing film of the year, generating $122 million in North America and more than $200 million worldwide in box office. In a 1991 interview, Clancy remarked of the film's success: "It was reasonably true to the spirit of the book, although the movie