So far I have tried soft scrub, westleys bleach white, simple green and I still cant get it white. Its an old excalibur hawk 39 with the whole deck being non skid, its a project to clean!!!!!!Help!!! How about some muretic acid?

I was suprised to find a product called x14 mold and mildew remover it is a bleach base cleaner great for boat seats also non skid I spray it on let it sit for about 10 min then scrub it with a stiff tire brush you will be suprised my wife figured it out good luck then put mcguires detail and polish to seal it

Where do you get that stuff?

Acid will clean but cut it with water. Its the active ingredient of many fiberglass cleaners. If there is any chance of it contacting polished aluminum do not use it. Be very careful with your eyes and skin and try a small test spot before commiting to using it. For my fish boat with a sprayed gel interior I mix Dawn dish detergent (a good squirt) with about a cup or two of Bleach topped off with water in a five gallon bucket. Use a good brush and it will clean up well.