If you measure every time you sail, you will get a better polar diagram for your skill, not neccessarily for how fast you could go <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />


If you lack GPS units at the GC08, I can lend out my old Garmin eTrex. As long as I get it back when the event is over, no worries.