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. The simplest type of chine construction is the single chine "v" shape, with two flat panels joined at the keel (a). this type of hull is among the simplest to build. Design software: aerohydro (marine design and modeling software and services) aerologic (lofting, simulation and analysis software) aeromarine research (tunnel boat.