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 of use there is not a single problem with that. Epoxy resin sealed all. Just have to use epoxy, not polyester or vinilester resin. And to be sure that there is no places without epoxy cover.
Hi Milos,