Unfortunately I didn't take a "before" shot (it was ugly). Mildew had completely taken over and this 2001 dinghy was a splotchy and streaky black below the midline of the tubes and between the ridges of the rub rails. The aft ends of the interior tubes from transom level (and down) were black. I had tried acids, household cleaners and the strongest inflatable boat cleaner I know (Nautical Ease). Ordinary bleach diluted 1 part bleach to 3 parts water did the trick.