Balsa Core Decks.

[Scotty_Tradewind]

Good write-up here on how to prevent water getting into the core form holes for deck fittings etc: http://www.pbase.com/mainecruising/sealing_the_deck&page=1

A really good write up.... by 'potting' the holes you can really beef-up holes such as those which hold chain plates, so that the backing plate can be torqued up without fear of compressing the deck either from the top or the bottom.