comments:
I have this cleaner: https://a.co/d/0gJiuyRu I haven't had any stains quite as big and crazy as you have right now, but I have gotten small areas of brown from gross ponds and I also paddle a lot in the sound in NC and it can get pretty gross. And it always gets it out pretty good for me. I use it with a microfiber towel and it usually gets out everything and brings it back to bright white. It's worth a shot and isn't super expensive, plus an added benefit is it smells sooo freaking good, idk why. Otherwise boat vinyl cleaner would be your best bet if not, as it's gentle enough for the PVC material, but also cleans well. PS. Do not use magic erasers as everyone is telling you to do. The PVC the board is made of could really get scratched up and ruined and it's not a good idea. You need something way less abrasive. These people clearly don't understand what the magic erasers are lol