Never cover a hull with any type of coating if you can not immediately have a treatment performed, which

1: Can post cure all of the under water hull.

2: Can remove all acid residues and styrene.

     It is the acid that is aggressive, not the water!!   As more water that can enter the laminate as more diluted and less aggressive becomes the acid.

     If the blisters are only sanded or blasted open and then covered with the antifouling only without any filler, the damages to the hull will proceed at a slower rate.

     A later proper repair will be much cheaper, than if not diluted acid is allowed to accelerate the hydrolyse under a water shield coating.