For hard polishing and ablative antifouling paints with heavy contamination, use a paint-stripper to remove all the pollution and the paint. For light contamination, powerwash and then use a household detergent with water to scrub off any pollution. In both cases, you should then scrub the substrate using Fiberglass Surface Prep YMA601 and a coarse cleaning pad before rinsing with fresh water.
Contaminated topcoats should be cleaned as soon as possible to minimize the damaging effects of the crude oil. Always test a small area before cleaning the entire boat.
With heavy contamination, wipe down with T0016, T0170 or mineral spirits followed by power washing, and then clean with a household detergent. Each area should be rinsed with clean water.