Chris, I believe that all the M15's were built with a light, 55 lb., centerboard made of fiberglass. That is why no winch is needed to haul the pennant up and also why the relatively light weight of the board can be supported solely by a knot in the pennant, unlike the heavier cast iron boards used in the earlier 73 to 89 M17's. 89's to the present use a light fiberglass board similar to the M15's. As I say I think this is correct, if not I'm sure there are many on this forum, especially the builders, Jerry and now Bob, who will correct me. _________________________________________________________________________________________________ Fair tide and a steady breeze, Nick