I have an old 16' fiberglass semi-v boat with a closed bow. There is a bench seat about 3/4 of the way to the stern that is basically a hollow box. I am thinking about cutting the top off off it, dividing it in half (or 70/30) and glassing the inside of it. I'd make a new top for it (also using fiberglass coated wood) with a waterproof hatch for each side. Half would be styrofoam lined to make a cooler and the other side for a live bait well. The drain for the cooler side would just be tubing with a small ball valve to the bilge and bait well side would drain to bilge and fill with tubing over the side or a long piece of tubing below the deck to the transom and over. I know filling from over the side is cheesy, but a badly done hole below the water line would be worse. Neither space would be huge, but they would be enough to save the floor space taken up by a cooler for cut bait and a live bait bucket. Does this sound like something I could do without compromisinig the structure of the boat?