No re-inforcing structure in the floor there. There may be extra glass from the one piece floor which was set on top of the inner side of the hull. Not structural. Be sure not to invade the core if you are smoothing the hole etc.
You still want to have a fitting to remove any water--because some boats which don't have a drain hole there, got water under the floor. Logical place is just outside the cabin door. Small access plate would work there,
You still want to have a fitting to remove any water--because some boats which don't have a drain hole there, got water under the floor. Logical place is just outside the cabin door. Small access plate would work there,