Reply To: Downwind
try with no cunningham as that just opens the leech more at the top making it more unstable. I am not sure how much you had the board up but if it was windy then about half up is fine. If you have an alloy mast then get a carbon one asap as they make it a lot easier to sail downwind. If you have a soft alloy one then with 90kg on the back the mast is probably disappearing over the front of the bow which also makes it very hard to control. Otherwise a lot of practise comes in handy.