The sticker indicates that the boat bottom uses 100% non-toxic antifouling paint that is also hard-wearing and resistant to brushing. The symbol communicates to boat wash services and boat clubs that the hull is safe to clean without special arrangements. By using the sticker, you also spread the message to fellow boaters about ecological antifouling that does not rely on toxins or soft, easily worn plastic surfaces that release microplastics into waterways.