Scratches and swirls on the surface of a boat are caused by improper boat washings. Dirt and grit from the boat’s surface are trapped in mitts and brushes. The Grit Guard Insert keeps dirt and other contaminants away from your wash mitt or brush. Grit Guard is a wash bucket grate system that prevents your brushes, sponges and wash mitt from reaching the bottom of the bucket where the grit in the wash water settles.