Boat fenders prevent damage to a boat when tied to a pier, since they stand between your boat's finish and the pier itself. To make one, lay a line out in an S shape. Pass the bitter end through the bottom loop and then begin to make turns around the 2 bights, so as to form the central core. Tie a figure-8 knot as close to the top loop as possible. Tighten the top loop by pulling on the bottom loop and tighten the bottom loop by pulling on the top loop as well. Turn an eye splice as close to the top of the fender as possible. Lastly, paint the nylon rope to match your hull or to make it into a colour that will stand out in your deck gear box.