"VG" wrote...
what are the limits of plywood boats ?

I am interested in kind of ultralight (25000# to 32000# light) trawler in
the 42-50 feet range, of displacement type, not semi displacement. No intend
to exceed hull speed. So single engine could be in 100-120 hp range.

Plywood construction, easy to build. My father is a retired woodcrafter, and
I found at home an original copy of heavy weather sailing by Kadlard koles.
He has owned several sail boats, but never powerboat and never built one.

Devlin Designing Boatbuilders in Olympia, WA builds stitch & glue plywood/epoxy
boats of all sizes -- power, sail, and oar. Plans are available for many
designs. See http://www.devlinboat.com/. In the size range you specify, he
has:

Czarinna 43 -- 19,400#
Oysta 42 -- 24,000#
Golly Wobbler 43 -- 21,000#
Sockeye 42 -- 30,000#, 45
Kokanee 43 -- 28,000#

Sam Devlin had a flotilla of his boats from 18 to 43' long (including a Golly
Wobbler 43) at the Port Townsend Wooden Boat Festival last weekend. They were
all beautiful!