Good advice there - I agree - easing the sheet before you stuff into the back of a wave is essential to staying out of trouble.

I've just remembered a great gybing technique from Rick White's excellent book 'Cat Sailing for the 90's':

When gybing in heavy air as the boom begins to come across head the boat down wind a little - this stops the boom swinging so violently. It's a good technique for heavy air (which tends to go with big chop).

Chris.