I've been having a great time sailing in Second Life. I bought a Flying Tako a couple of weeks ago and I've spent a bit of time learning the boat, how to sail in Second Life, and trying to find good places to go. I'm more into open water sailing where I can find it. For maximum geekiness, I shot a screen from some sailing I was doing tonight.
Makes me wonder where the good/boxed PC/Xbox 360 simulation is for this activity. For information about sailing in Second Life, I suggest the Second Life Sailing Federation. There's a FAQ to help you get under way. Getting started in Second Life is free and a sailboat is dirt cheap. Let me know if you try it out.