GB, the thing about the waterproof/water resistant bit. . . actually all the makers of ply are using basically the same glues, and the quality of the glue in our cases to be total honest, while important for the plywood initially, (some of the guys may disagree with me on this, but it is how I see it) once the boat is given a GOOD saturation coat before applying the glass, the epoxy basically overrides the glue already there. And the GOOD saturation coat helps in the prevention of dry rot later on down the road, if the boat is cared for properly. So, the waterproof vs water resistant, in my book anyway, is not an issue. A thorough saturation coat , inside and out, will be the answer for all ply. . . cheap or expensive.