Especially in marine water, the unwanted accumulation of microorganisms, algae and animals on wetted surfaces can be costly if not attended to regularly. For recreational or commercial boaters, the danger of transferring non-native species is added to the increase in fuel consumption and maintenance cost. The navies of the world are not immune to this plague either. One study roughly calculated the cost of coating, cleaning and fouling on the United States Navy’s destroyers (class DDG-51) to reach $1 billion over 15 years!