Hi Wouter,
The one I know of is clled Virtual Sailor (as opposed to Virtual Skipper) not too sure if it`s the same as the one being mentioned by others. I haven`t seen it myself, but a while back I bought the Hangsim program from them, a flight simulator for free-flight gliding, paragliding, hang-gliding & microlight flying, which is much too realistic, it has you leaning over in your chair as you do a steep turn !
Check out the link to virtual sailor:
http://www.hangsim.com/vs/

Cheers
Steve