Common problem with these boats. Mine's doing the same thing. It's not the graphics that's delaminating, it's the wall itself. The walls are about an inch thick, most of which is high density styrofoam (not sure of the technical name), faced with (I think) some 1/16" thick wood (or plastic?), and THAT is covered with a thin white plastic (vinyl?), and THAT is what's delaminating. Or warping... Sorry if I sound about half stupid but I'm not near the boat and it's been awhile since I have been!
Short version, the sun is killing it, and I'm not sure what to do about it short of pulling all the facing off and starting over.