I've only taken my boat on and off the trailer 3 times now and I'm already getting these black scuffs on the keel. What do you all do to avoid these marks? I have found a product shown here but with the color of my boat Im not really keen to put this on.

Also, if I do decide to go with this product does anyone have any tips on how to get it on? I assume I would have to be in shallow water (possibly at the dock) to have the boat off the trailer and then stick this thing on.