Been there, done that!  I have a 1979 Marina Trader, 34 DC, that I 

    This produced a deck that is strong, stable (read "no trampoline 

Been there, done that! I have a 1979 Marina Trader, 34 DC, that I purchased in Florida last May. I bought it knowing there was a problem with the deck. Didn't need a surveyor to tell me either. Walking on the deck was similar to treading on a trampoline with the added visual of little squirts of water popping up from the screw holes minus their bungs. The previous owner saw that as no problem because there was no leaks down below. I could visualize a problem with freezing and heaving in colder climes up north where I was taking the boat. My solution was basically this: 1. Ripped up the old teak and discard. 2. Cut sections of the glass deck exposed in sections about 3' long and a 1" in from the cabin side and gutter side. (I know there must be a proper nautical term for that but I forget). Sand clean and smooth this section for reuse later on. 3. Clean out the exposed plywood filler. This was in panels about 8" square and completely laminated 4. Dry, clean and sand the void produced. 5. Replace the plywood with 1/2" PVC high density foam, bedded in thickened epoxy. 6. Replace the clean sections (see #2 above) bedding them in thickened epoxy also. Often I used epoxy wetted matt to gain a surface level corresponding to where the old glass deck was. 7. Over this 1/4 PVC panels bedded in thickened epoxy. 8. On top of that two layers of biaxial cloth well wetted down with epoxy. The 1/4 PVC and the biaxial cloth was edged on the "gutter" side with a 1/2" molding of teak to give a finished edge. This molding was made from some of the old teak deck. I did not rip up the whole deck at one time as I had visions of the cabin structure falling into the bilge. I worked in sections about ten feet at a time. This produced a deck that is strong, stable (read "no trampoline action"), leak proof and at the same level as the old teak decking. Ergo, no problem with the thru deck fittings for fuel, water. and holding tank. To hold recalcitrant panels of the old glass in place I used sheet metal screws sprayed with "Pam" and/or gallon water jugs sitting on plastic sheet to prevent them from becoming a permanent fixture on the deck. I have yet to put down any nonskid surface. It will be some variation of paint and grit. This project took me from June to October. I was lucky in that it was a dry summer and I never was held up by rain. Hotter than H*** however so my work day was never much more than five hours. I had gotten estimates from yards in the Annapolis area of as much as $20,000 to do the job. I have yet to calculate my cost but feel confident it was no where near that high figure. I do not profess to being an expert on FRP work. I'm happy with what turned out and only time will tell if it was done the best way. Charles Monroe, EBB TIDE, Pt. Patience Marina, Solomons, MD