This is a very bad example of exactly what you don't want to see, a totally saturated core. This boat lives on a mooring and this is one of the primary mooring cleats. Perhaps there is likely some serious delamination going on and degrading or degraded core as one would assume. This core however was routed out around the bolt holes and found to be dryer than would have been expected. Meters can read metals and perhaps a backing plate so this reading was not as accurate as one would like it to be.
Remember the degradation and physical rotting of the core begins around 20% on the CT-33. The longer it has been above 20% the more likely are the odds for a total failure and delamination of the skins but this can still take a long while. I have seen decks with 25% readings going back 10+ years be taken apart only to find that they were damp, but still very, very structurally sound. ALWAYS incorporate spot soundings and core samples BEFORE digging into a deck.