I have a feeling this product works similar to Dura-Bond. It's a 2-Part Epoxy. Looking at the website, it says Damp/Wet. I do not think this means underwater. If you were to safely drain to this level, I don't see any problem usuing this. You'de have to prep the area first, like sand or remove any existing paint, but I don't see any issues. The site states " can be applied in dry or damp conditions on metal, concrete, and fiberglass surfacess." So I would verify "underwater" painting. I am not familiar with theh brand, but I would check.
