The bottom of my boat was lookin a lil rough because Im a lazy azz when it come to cleaning. What I thought were scatches and stains came completly out all over the boat, mainly the hull. Anyway, it does work great, especially on white. One thing though, I did try it on a little a mark on my motor cowling, kinda scratch it, no prob though, I had some 3m marine wax here, put some on, and everything is fine. I would not recommend for the motor cowling. Again, for a “WHITE” boat you have to try it. Wyatt