On Thu, 16 Jun 2005 21:22:10 GMT, "Bill McKee"
wrote:

Marine ply rots just like any other ply. The only difference between ACX
and Marine ply is the Marine has no internal voids. In a small engine
powered boat, the voids probably do not matter as to strength.

I wonder if the Doug Fir used in exterior softwood ply is more durable
than the cheapo hardwood used in normal exterior and some marine ply.

Ply can be treated though it takes time to dry out, also there are
borate pellets that are put into the wood and release preserver if it
gets damp.

Maybe the OP should take a look at treated green ply for use 'below
grade', if it's covered in fibreglass it shouldn't look any different
in the end.

cheers,
Pete.