The 80 hours quote is just to have the hull finished. This means wood cut, spliced together and the seams and bottom probably glassed and that's about it. Maybe paint before flipping. The decks, consoles, topside paint, wiring will require more than that.
Below is a quote from one of their VERY straightforward boats, the 18' garvey which is their version of the Carolina Skiff or jon Boat, note the claim between hull completion and finished boat.
Complete boat at 2 1/2 times that of just building the hull, so a hull at 80 hours really equates to about 200 hours for the complete boat=5 weeks full time, probably about right for a 16' boat.
The hull can be build in 25 hours but a finished boat will require 60 hours or more depending on the level of detail and the skills of the builder.
Bateau's building method is based on stich and glue. The plywood is cut with a circular saw or jig saw in some cases. then the wood drilled and either taped together or tied toegther with wire ties. Then the seams fiberglass taped and the bottom covered with glass and the sanding done. At that point the hull is built, as they claim.
"The Chesapeake does not impress those who know it best as the grandest or most of anything. For all its size and gross statistics, it is an intimate place where land and water intertwine in infinite varities of mood and pattern."
William W. Warner "Beautiful Swimmers"