Hi milos, plywood used for kayak on pictures and videos is a regular one. this same non waterproof plywood is used in doubletrouble too. and for more then a 3 years. Stitch and glue is a simple boat building method which uses plywood panels stitched together, usually with copper wire, and glued together with epoxy resin.. If you want to build a boat, we have what you need. chesapeake light craft is your source for boat kits, kayak kits, boat plans, and boatbuilding materials..