Easy fix
garden sprayer filled with 50/50 bleach solution on a hot dry day. spray it on, let it sit, hit the spots tht are still stained again, let it sit, hit the ....... let it dry , the smell will dissipate eventually and the residue seems to inhibit the regrowth.
wear clothes you want spotted, goggles and gloves a real respirator if you have it. If not make sure the boat is ventilating or you'll burn your sinusses