I guess my fascination with submarines started when my dad took me to see museum submarine Vesikko. I was about eight years old then. Then I saw a movie called surprise surprise Das Boot. Later on I have visited Vesikko at least more than two dozen times. I even wanted to serve on a submarine during the mandatory military service, but thanks to Versailles treaty after the ww2, Finland can't have any.
Later came Silent Service and then Aces of the Deep, which still is IMHO better game than SH3, without the sugar coating of course
But the german submarines, the silent hunter. They are cool looking war machines and as before said deadly. I can't give any better description because my english is what it is.