1999 Ranger Fisherman. Kids have been using the boat the last several seasons and obviously never wipe it down after leaving the water. There are times when they are able to leave the boat in the water for several days at a dock. I'm trying to remove the water line scum. Bar Keepers did a pretty good job of removing the scum line but it still appears dull. C Pic. Should my next step be using my buffer with a light grit polish and go over the area again. Any advice would be greatly appreciated.