I remember Silent Service *very* well, moreso because as a young budding programmer, it was the first commercial product that I bought that "let me" view the source code.
Game wise though, I vividly remember manoeuvring the white pixel to-and-fro across the map screen.
Actually, come to think of it, I *really* enjoyed it, like I did nearly all Microprose titles of the eighties (something about medals and ranks that I really enjoyed). I did hate the "what ship is this" copy protection though...