How do surveyors find this kind of problem? I’ve heard of spongy feeling balsa cored decks that you can feel when stepping on them. Do they use moisture meters in common problem areas, I.e., penetrations, and then draw likely conclusions based on that?Sometimes people draw a distinction between de-bonding of core to skin and de-lamination of the skin itself. I am sure PVC core materials such as divynicell don't rot or spread moisture as fast as balsa, but moisture is still not supposed to be in there and it can still cause problems such as progressive destruction of core/skin bond or whatever. All cored boats need to manage moisture intrusion into the core. Also, it is imossible to build a light rigid boat without either a core material or a large amount of stringers and other reinforcement on the inside of the hull.