The port side salon windows in my 1996 325 aft cabin lost their seal and water came into the walls. There is some damage to the floor plywood and the board inside the wall between where the fuel vent is and where according to my carver manual an optional battery can be placed. The picture below (not sure why it is rotated, can’t fix) shows the board without the white ring. I am removing as much of the damaged wood as I can and drying the area out with fans. The other side of board has the foam pads, maybe insulation.

Is this board necessary?

My plan is to remove as much of the damaged wood as possible, dry it out, treat for mold, epoxy the floor plywood. Has anyone ran into a similar situation, any and all tips are appreciated.

Thanks,
Drew