Hull cleaning

Hull cleaning is the removal of marine growth (biofouling) from a ship’s underwater hull and niche areas to restore smoothness and cut frictional resistance and fuel burn. It is done in dry dock by grit blasting and recoating, or in water by divers or remotely operated tools while the ship is afloat. In-water cleaning is governed by the IMO Biofouling Guidelines (Resolution MEPC.378(80)) and by local port and state biosecurity rules, with capture of removed material to limit invasive-species transfer and antifouling-paint release. Heavy fouling can add double-digit percentages to fuel consumption, so cleaning intervals tie directly to hull-performance monitoring and the antifouling system’s service life.