Surveying fiberglass boats during the winter months poses some difficult issues. When the ambient temperatures are below freezing any moisture contained in fiberglass structures, such as boat hulls and decks freezes as well. During the freezing process crystallization of the substance occurs adding small air pockets which make electronic moisture detection virtually impossible. Also because the substance is frozen it becomes very hard rendering percussive sounding tests useless as well. It is for these reasons that I do not recommend surveying of fiberglass boats when the ambient temperatures are below freezing. Any surveyor who claims that their inspections are valid under these circumstances is in my opinion simply not being truthful and should be seriously questioned.