Back to the "how to get the centerboard out" discussion: to get under Rocinante, I just pull/push her off the trailer onto the grass and roll her on a gunnel with a 2x4 to keep her from going too far over if necessary. It allows me to paint her bottom, check the centerboard, install a half-round back to the keel... I wouldn't leave her on her gunnel for months at a time, but to make necessary repairs, why not?