The following is a short description of the important characters in the book. This includes characters that may or may not appear in other books by Clancy. If there is a difference between the book and the movie, it is indicated by brackets: [movie changes].

Greer, James, Vice Admiral
Retired Naval officer. Deputy Director (Intelligence) of the CIA. Widowed, 1 son (KIA, Vietnam).

Moore, Arthur, DCI.
Former judge of Texas State Supreme Court. CIA Director. [In movie, seen only during the briefing.]

Petrov, Yevgeni Konstantinovich, MD.
Doctor on board the Red October. Perfect communist.

Ramius, Marko, Capt.
Captain First-Rank in the Soviet Navy. Lithuanian born, father was a powerful Cumminist figure. Tought at the Frunze academy. Became a "test pilot" of new soviet submarines. Widowed, no children.

Ritter, Robert.
Deputy Director (Operations) of the CIA. Career CIA man. [Does not appear in movie version.]

Ryan, Jack, Ph.D.
Ex-marine and ex-stockbroker. Recieved a Bachelors in Economics from Boston College, and a Doctorate from Georgetown in History. Tought at the US Naval Accademy. Currently working for the CIA in London, England. Married, two children. [Movie indicates degree from USNA.]

Tupolev, Viktor Alexievich.
Captain Second Rank in the Soviet Navy. Commander of the V. K. Konovalov, Alfa-class submarine.

Tyler, Skip.
For submarine captain. Lost his leg in an automobile accident with a drunk driver. Teaches at US Naval Academy, does consulting on the side. Married, 5 children. [Movie shows him at shipyard, mentions consulting done at USNA.]

To be updated...