In-Water Cleaning

In-water cleaning is the removal of biofouling from a ship’s hull and niche areas while afloat, sitting at the interface between the Anti-fouling Systems Convention and the BWM regime rather than MARPOL. It is addressed in the 2023 biofouling guidelines (MEPC.378(80)), which replaced the earlier biofouling guidance, and which set expectations for capture of removed material and management of antifouling coating debris. Effective biofouling management cuts both invasive-species transfer and the added hull resistance that raises CO2 emissions, linking the practice to CII performance. Port and coastal States set their own in-water cleaning permissions and capture standards.