This was one of the big "trouble spots" in the floor. A previous owner cut these holes for access to the fuel guage connector wires and fill hose on the gas tank. They did a good job of covering them with watertight hatches, but did nothing to treat the cuts in the wood - ie sealing or glassing them. Over time water has crept thoughout this area of floor, between the fiberglass layers and eaten away much of the wood. This flooring section will definitely have to be replaced.