I had this happen to me
I had my center board get stuck, and I had to pull it down. What happened in my case was that we replaced the centerboard pendant with a new line. The old one had the wire going right into the back of the centerboard, but the new one came with a shackle that I had to attach to hole that I had to drill in the trailing edge of the centerboard. The origina shackle had a screw and nut that were too wide for the centerboard trunk, so when the centerboard was pulled up, the screw got wedged into the top of the trunk. the screw was later replaced with a clevis pin and cotter pin combination that was just about an eight of an inch shorter than the screw. This was enough to keep it from getting stuck.Anyway... How did I get the centerboard unstuck? Here is what I did... I took an old piece of wire from my old set of standing rigging, and made a large loop, maybe two feet in diameter. I took an crimped the wire at both ends to make it more football like in shape. I inserted the kinked end of the loop into the back of the centerboard trunk, then moved it forward to get it looped around the centerboard. I then was able to put the handle from my bilge pump through the other end of the loop, and pull down on the centerboard. It was extremely difficult, and was well wedged into place. I had a scuba tank on my back when I did this, and was actually standing upside down with my feet on either side of the keel. when the centerbard did come down, I moved swiftly out of the way to protect myself. However, it did not fall as quickly as I thought it might.Best of luck!Michael Gordon