deck core problems

I know that many of this lists participants have been owners of BCC’s
for a long time and/or have older boats. Have any of you had problems
with delamination of the plywood deck coring or problems associated
with degradation of the core because of water intrusion?

You may want to investigate the use of clear penetrating epoxy sealer (CPES) by Smith Co.  The Rot Doctor at http://www.rotdoctor.com  is the vendor for CPES.  I have used this material in boats and in houses with good success.  Because US built BCC's have a plywood deck and cabin core, this epoxy could be used to seal the wood where bolt holes and screw holes go through the deck.  CPES is also being used as a primer for polysulfide and urethane caulking compounds - WoodenBoat Forum at http://www.WoodenBoat.com .
The attached image is the BCC "SIRIUS" anchored in Baltimore's beautiful Inner Harbor.
Rod
S/V IDUNA