Anybody know if there is a way to tell marine vinyl from the regular stuff. I have a roll (15 yards or so) of white vinyl that came with a boat I bought a few years back, guy said it was "marine" but it has no markings on the back. I thought all the marine stuff was stamped. I was going to use it to cover some side panels and speaker boxes, but I would rather not waste the time if it's going to disintegrate in after a year or two.