I recently bought a O'day 20 that had been in the water for some time. The centerboard was stuck in the up position. I tried to loosen it while swimming under water but, it wouldn't budge. I finally had to haul the boat out to paint the bottom. It turned out the centerboard was encrusted with oysters so there was little chance I could have cleared it.I've since heard stories of divers getting whacked when the thing finally comes down so I'd be careful. Good luck.
