Sounds like you need alot more downhaul when the wind gets over 12 knots to me.
There are some adj. downhaul systems, but they are complicated and
worked best on race longboards back in the day.
What's you next size smaller sail?
Maybe the 12.5 is just too big for your skill level, and you would only need to use it
when the wind is < 10 knots.
Something around 9.0-10.0 should work well from about 11 knots to 15 or 16 knots for sailors over 165 lbs.
Are you good at pumping?
If you work on your pumping skills you can get by with about 1-2 m2 smaller and still get going in the over 10 knots wind range. Below 10 knots, you need the bigger sails and pumping as well.
Have you learned to "pump the fin"?
A few quick thrusts with your back leg/foot can really loosen your board up on the water and launch it onto a plane.
Hope this helps,
Last edited by Roger; 24th October 2009 at 01:17 AM.