Hey everyone we have encountered something I have not seen, this is in one of the staterooms, after removing some of the headliner and wall coverings we found this discoloration in the fiberglass. My fiberglass guy says it’s the layers becoming separated, they feel not as solid when sounded with a mallet. No damage ya seem from outside the boat it’s seems it’s in the top layers. Any help and direction with this, curious to what it is and steps to fix it. ThanksBrooks