Wanna-be pilots have Flight Simulator, Microsoft's iconic computer game, but what about those who want to steer a cargo ship? Enter PlanetInAction's "Ships", an online simulation that uses Google Earth to let you get in touch with your inner helmsman and steer your own fleet of ships from barges to the cruise ship Queen Mary 2.
Link | YouTube Clip - via Kris Abel's Tech Life
I know I am ruining all your fun! sorry...
There's also boats you can get for Flightsim. I remember tearing around the water near Meigs in a Coast Guard vessel. Good times:)
http://www.shipsim.com/home.php