Just wanted to report on something that really worked as it is supposed to. I pulled out the sole of my boat to refinish it this winter. Underneath was some of the ugliest dirtiest and scuzziest fiberglass around. 23 years of being hidden will do that. Dirt, mold, diesel, oil etc. Wondered how to clean it. Didn't want lots of chemicals since it is an enclosed area, even with all the hatches open. Well, I picked up a 'steam vapor cleaner', and it worked miracles. It puts out high pressure steam at 65 psi and 305 degrees. Just a touch of degreaser and this got everything clean and smelling good. I will probably try it on the deck gelcoat in the spring. They are not cheap (I got mine used off Craigslist), but it was worth every penny. (Of course now I am doing the tiles, grout, sliding door tracks around the house etc.)