I've worked on boats with delamination but in those cases there was not the waviness, just a soft deck when the fiberglas separated from the core. A good repair depends largely on the condition of the core material. If the core is rotten it's unlikely you can get a solid bond with the skin. I've fixed some cases by drilling holes in the top and bottom of panels and injecting into the top hole with WEST system epoxy. Screws drilled through the skin into a solid core will clamp the pieces together. When dry you can removethe screws and patch the screw holes. Success all depends on the condition of the core material
1998 Newmar Dutch Star, 3126B Cat/ Freightliner
2003 Honda Element
" Don't let the same dog bite you twice "