"Plywood substrates should be avoided, whenever possible, for use with
Formica brand
laminate,

Huh? From the Formica site it says"

Plywood
• Excellent substrate when from straight grained, low density hardwood
or softwood with surfaces free from knots.
• When bonded with waterproof adhesives (bond Class 3 of EN 314-2) the
composite boards suit applications subject to high humidity and frequent
wetting.
• Available in flame-retardant grades to produce composite panels that
conform to fire performance requirements of the Building Regulations.

What am I missing here?
There is a Laminate counter top on my 1977 sailboat that has been open
to the atmosphere for 10 years and the bond hasn't broke yet.

http://www.formica.co.uk//index.cfm?...y&ContentID=81