boat stains

Question
I keep getting black lines running down the side of my boat
from the snaps for the mooring cover, is there any way to stop
these unsightly bleeding lines?  

Answer
You could seal the snaps of your cover so they will not bleed.  I would clean them with a phosphoric metal prep. Then use a finger nail polish, two part epoxy, or good enamel to seal all the metal.  If you go to www.boat-bottom-paint.com you can get a $1.00 sample of a Teflon coating that could work vary well.