I have a set of plans for a Glen-L TNT and I've decided to build it.

The question is what kind of plywood or plywood substitute? The marine
grade ply of 20 or 30 years ago seems to be history.........

What else should I consider using? The finished boat will be used as a
knock about, not a show piece with forty coats of varnish. It will be
USED as a boat, so I think the inner plywood could merely be varnished
yearly, the outer skin should be glassed from chine to chine or maybe
from gunnel to gunnel.

What combination of products do you experienced boat builders
recommend?

I'm located in the Twin Cities and that might affect some of the
choices.

TIA