Nesting osprey on a ledge marker near our mooring in Casco Bay were very nice touch....until one of them landed on our main sail cover and had a fish feast - long enough to make room for more and leave plenty o'mess both on the deck of the cockpit as well as the main sail cover. Of course, it was a during a period we were away, so it had time to bake on. Some leached through the main sail cover - appetizing ey? - and now there is a brown stain on my main sail, maybe 1' x 2'. What is the best was to treat that back to white tinge without damaging sail? Stock sail from Hunter in 2004. I also figure that a line running across there now should be enough to discourage them from revisiting for lunch. We'll see. Thanks, Roger