There's no pin, it just pivots into a pocket that isn't even really tight. When it is all the way down, the line is very slack, but if it is the same as it was before you launched, it might be stuck. Have you checked the line in the cabin? It runs inside a white corrugated plastic hose in front of the compression post on mine. You could loosen the attachment on either end, or, if it's like mine, the hose has shrunk to where the line is visible at the top. If the line is taught inside the cabin, it could be binding where it passes through the deck. The board is pretty heavy and should easily come down normally. I would think if it's stuck, it wouldn't take much to free it. Just curious, have you tried to raise it? It's pretty heavy at first and may not feel like it's going to come up, but once you get it started, it moves easier. One other thing just came to mind, occasionally, when lowering the rudder, the line used to raise/lower it gets jammed between the rudder and the mount and the weight of the rudder really binds it up. I have never taken my centerboard out and am not sure if it could happen there, but it seems like a similar system. Maybe some others could verify.