MacSailing.net

Does anyone know of any race planning software for the Mac (or even the PC under VirtualPC)?

I'm taking part in the Round the Island race (Isle of Wight, UK) this year, and need to be able to course plan with tidal flows and weather files.

I have heard good things about this one..

http://www.iexpedition.org/

But expensive.

Stay away from anything Raymarine offers (software or instruments).