Lots of funny waves & things off Manitou. It''s quite likely your leeway kept you from going over. I''ve seen Lightnings moored in Larchmont(NY) with their sails & rudder off, but which left their boards fully down, capsize because they couldn''t swing around fast enough in a stong, shifty wind. Having the board down part way may have helped dissipate the force of the wave with more leeway, and the raised board tip may also have made a less powerful fulcrum point for the boat to pivot around, resulting in less heeling too. Theoretically, the centerboard keeps the boat from slipping sideways though the water. Since the boat can''t slide sideways, the wind on the sails makes the boat heel instead. Having the board up can mean less heeling -- you slide sideways more, but stay upright while you do. Sailing is a balancing act, all the time.