I noticed in the Archives that John K asked a question last month about products or methods to remove stains. I was away and did not notice this post. For what it is worth, I have removed lots of "stains and marks", from black scuff marks from rigging and shoes, to real stains from red my tie down straps leaching pigment onto the hull where they touched (when they were new) from my 170. I have had excellent results using Starbrite Premium Marine Polish with Teflon. I don't think that the teflon has anything to do with it (it is what I use on another boat and had a bottle handy), but the polish works with almost NO elbow grease. Put some on a soft rag, swirl around a bit and it is gone. Better yet, there is no trace on the hull that a mark existed. Works well. Available at almost any local boat products store or online at..........www.westmarine.com. Rusty