I recently made some coils of rope that turned out quite well. Here's how. I took braided nylon string (kite string, household twine, etc.) and coiled it to the desired shape. I then placed the coil on a flat surface and pushed straight pins horizontally through the windings to hold the shape. Next, I diluted some white glue (Elmer's, here in the USA) with a little water and brushed the solution onto the coiled "rope." When that dried, I painted the rope, removed the pins, and attached the coil to the deck. Easy, inexpensive, and effective.