The butterfly coil is the simplest and quickest way to coil and securely store a length of rope longer than 20 feet. The knot also uncoils easily without forming kinks. So, if you have tangled piles of rope and parachute cord in the basement or gear closet, this knot will help you get them organized and accessible.
Double your rope, then hold it at its midpoint. With your hand open and perpendicular to the ground, drape a 3-foot length over the top, forming 1 1/2-foot coils that hang to either side. Repeat until 6 feet of rope remains.
Starting from the bottom, wrap the coils tightly, making sure to wrap over your first turn so that the wraps won’t unwind. Stop a few inches from the top, double the rope you’re wrapping with, and pass this loop through the opening left by your hand. Bring the tag ends over the top of the coil and through that loop.
Pull tight. For more security, you can tie an overhand knot around the final loop to keep it from sliding.