The O'Boy 25 has a pin that passes through the hole in the centerboard or swing keel that is kept in place with two wedges, each on each side of the centerboard trunk. There is a plate (as I recall) that holds these wedges in place. Unbolt the plate and the wedges fall out along with the pin and the centerboard. Pretty simple, actually. Most likely the rope is jammed between the centerboard and the wall of the centerboard. Can't tell you what the leak is about. You have to stick your nose around to find the problem. Good luck.