I have sanded the entire area clean to the glass. No cracks, flakes, or anything of that nature just a "light noise" when tapped instead of "solid". drain plug won't budge in the least.. so no play. The seam also looks fine no stress cracks or fracturing in the fiber or glue.
Can I just sand into the void, visually inspect, and lay new glass in? It would be solid and would structurely be as new again instead of filler, or am I way the hell off base and just looking for a ton of work? I mean I've completely sanded the entire hull and keel someone asked me why the hell I was sanding it that much, I said so I knew exactly what she looks like underneath, if that gives you any indication as to me and this little boat. I don't mind the work I just don't want to ruin her by doing something foolish.