Silent Hunter is submarine simulation developed by Aeon Electronic and published by Strategic Simulations in 1996 for PC MS-DOS only.
This World War II submarine combat sim was created mostly by William T. Becker (programmer) and Kim Biscoe (artist). You are a commander of a U.S. submarine during the end of the war (after Pearl Harbor) and your task is simple: sink as many ships as possible. You can either play historical missions or random encounters, but of course the career mode is the most interesting. Submarines, ships and weapons reflect what was available at the time, making the game very realistic.
Silent Hunter was a success, with more than 300k units sold and very favorable reviews. You can't miss it, especially if you love war simulations.