bigfoot and northern lite details on their construction

It does say on their website under construction.
Once both the top and bottom are pulled out of the molds, the top shell is placed over the bottom shell which has a plywood lip along its top. I'm guessing it's the whole seam this plywood lip is. They should treat this wood and other bare wood with a moisture resistant stuff. Probably would double the life of this bare wood if it was to get wet numerous times