Removable interchangeable machine washable covers for your MOmarsh Versa-Vest in Gore Optifade Waterfowl Marsh. Best Uses: The GORE? OPTIFADE? Concealment Waterfowl Marsh pattern takes into account how ducks geese and other waterfowl see. Rather than mimicry patterns that make the garment look like something the Waterfowl digital concealment pattern is intended is to make the garment appear to be ?nothing? to the animal.