The notches in the hull shapes are the stoppers to take the 6mm marine ply planks.
This greatly simplifies the lay up the the hull planks!
Supplier of Wooden Kit Boats,CNC design,epoxies,bronze nails,Beech,Ash,Teak,marine and exterior grade plywood,bending plywoods and Flexible veneer sheets. Agents for these and many other companies: North Sails,Harken,Lewmar,Ronstan,Raymarine,Yanmar,International Paints. See also our blog on cars,its another side of what we can do,try this link http://royckdboats.blogspot.com/