The chainplates on my Cruiser 37 go through the deck and are bolted to the hull inside a cavity, which is covered by a trapezoidal fibreglass panel. Water entering the cavity from the deck usually drains out through the lower edge of this panel. However, on one side of my boat, I now have nast rust stains descending from the lower edge of the panel. I'm thinking that maybe the drainage has become bunged up, water has accumulated, and rusting has occured on the fixings. So, I want to take the panel off and have a look. Has anyone done this? How is it held on? Please don't say Sikaflex....
PS The pic is the panel before the rust stains appeared!