If your just trying to fill holes someone cut mask back side with a sturdy tape. Gorilla tape possibly . First off sand a good distance out around perimeter . Start laying in saturated mating to build up layers extending first couple out onto sanded perimeter. That seat cut out is your flotation in a Ghenooe. The center seat/live well they removed provides strength to hull bottom & sides. Take a look at unmodified hull and you'll get an idea of design. Center seat /live well is built over a mold then glassed in at sides and bottom to hull. I,ve done a bit of glass repair on my Ghenooe thru the years and used just the available mat and Epoxy resin available in Walmart Automotive section. You could get fancier but really not needed. While your glassing check your center keel on bottom for cracking. Good time to reinforce the length of it as they tend to get a lot of wear there. Another way to fill void for glassing particularly on the large area is insert an appropriated sized section of resin soaked 1/4" plywood as a backer and affix . Then build your mat up on top that overlapping onto sanded area first couple layers. Assuming that's a 13' or is it a 15'? Good little boats in the right place and float on a heavy dew! I,m sure there's more skilled Fiberglass applicators on here then myself so stay tuned you'll surely get other ways of fixing it.
