Anti-fouling system

An anti-fouling system is the coating, paint, or treatment applied to a ship’s hull to stop the growth of barnacles, weed, and other marine organisms that increase drag and fuel burn. The AFS Convention (International Convention on the Control of Harmful Anti-fouling Systems on Ships), adopted 2001 and in force 17 September 2008, bans organotin compounds such as tributyltin (TBT) that act as biocides. Ships of 400 GT and above on international voyages carry an International Anti-fouling System Certificate; smaller ships carry a Declaration on Anti-fouling System. Port state control checks the coating and the certificate, and 2023 amendments added a cybutryne (Irgarol 1051) prohibition.