It's hard to find a hatch to fit these boats. I bought a used Gray Marine hatch for my boat off Rudy several years ago and it had a tiny crack in the lens. The adjusters and the hold down knobs were in workable condition and I wound up changing the cover and using the lens that I had made and installed it on my boat. I rebuilt parts of the frame where the hold down knobs come in contact.
I glued the lens with Devcon Plastic Epoxy and tried sealing it with Dow Corning 795 but every so often, I'd get a tiny leak coming in between the lens and the cover.
I talked to friend of mine who had accidental broke the lens on his O'Day 30 hatch and he told me that he used Dap Silicon Rubber Adhesive Caulking to adhere his new lens back in and it worked like a champ. So last spring I removed the hatch cover from my boat at the club dock and brought it up to the picnic table and removed the lens and cleaned the area good with denatured alcohol. I roughed up the inner frame and any area that the lens is adhered to, and I applied the caulking.
So far so good. I'm not too keen on using Dow 795 as my friend Jerry had told me that the stuff is just too messy to work with. I bought the clear stuff and I'm thinking that I would use it on any plastic material on my boat including the port light windows.
My friend Jerry bought a new forward hatch for a Pearson Ariel that he was working on. He had the same problem that you have encountered with a curved surface and an opening that wouldn't work for this new hatch. He's a cabinet maker by trade and what he did was make a frame out of wood that fit the contour of his forward deck and accept the hatch. This worked out well for him.
You can't raise a hatch to high because the sheets will get caught on it and this is the problem that you can run up against when you install a hatch this way.
I almost bought a used Aluminum hatch years ago in a marine consignment shop in Newport RI. I brought my old hatch with me to the store and went out to get it and compare it with the Aluminum hatch. They seemed to be the same size on the outside, but the Aluminum hatch had a smaller opening than my old hatch. It was so small that I could not fit through it. It would have looked great on my boat but what good is a hatch that you can't fit through? Not only that, but this hatch had a large hinge that may or may not have fit the recess on my bow.
As much as I'd like to have a new hatch, I'm going to try to keep the old one working for as long as I can. Good luck!
