Leaks
I have a 1975 O'day 25 which I purchased last fall. When I was fitting it out this spring, I found that I had some delamination on the side deck. After removing all the deck fixtures in the area and repairing the apparant damage, I found that I had a rather significant leak from that area. I finally tracked it down to a fairly large hole in the inner fiberglass layer from who knows what. It was well away from where any deck fittings including toes rails were attached. The water was getting in from cleat futher forward that I hadn't rebedded yet. I would suggest removing and rebedding all the fixtures in the area. If the leak persists, then you might need to make a small opening in the inner liner so you can see the under side of the cabin top. Then if someone can help you, have them use a hose and start spraying water one area at a time as you watch for any sign of water. If no help available, maybe try mixing some food coloring in a bucket of water, pour some on, go look for any leak, and so forth. If you use a mirror and flash light, you can see quite a bit of the cabin top from a small opening. You can use a small plywood circle or something like that to cover the hole after you've found the leak. Good Luck