I've just discovered that the Volvo Ocean Cup has an online game in which you can race against the actual fleet, in real time, using real weather.
Basically you pick your sail, and set your course (which could be a fixed compass heading, or a wind angle) ... and you race in real time against the actual fleet, and the rest of the world (at this minute there are over 75,000 people racing, and we're all trying to get to Cape Town first). You can log back in as frequently as you want, to check the weather and make changes to your boat ... but your boat will be racing 24/7. It's pretty fun.
The current Volvo Ocean leg (#2) is underway, so if you join now you'll be dropped into the middle of the fleet (in the middle of the ocean) ... but if this appeals to you, then I'd encourage you to get started now, to get some practice now ... and then we can compete against each other from the very beginning of leg 3 (Cape Town to Melbourne, which starts Dec 10th).
If you do register (it's free) then I'd encourage you to use your real boat name, so that we can find you. If anyone wants to add me (you can track your friends), I'm Canopus27.