Huh? The O'DAY 25 was built as a Keel/Centerboard or a Deep-Fin Keel, no "swing-keel" model. The Keel/Centerboard model did not have any way to lock the centerboard down, so something is "amiss" on your boat. Are you saying that the Centerboard is jammed in the down position? If so, you may need to either dive under the boat to investigate or better yet (although more $$) have the boat lifted out with a crane or Travel-lift and inspect the centerboard. It may be that something has wedged itself between the CB and the inside of the CB trunk (slot) jamming the CB. It is not impossible that the cb pendant (line to pull CB up) has become wedged between the Cb and the side of the trunk, perhaps by the Cb being pushed up as the boat entered shallow water.