Ships travel faster through the water and consume less fuel when their hulls are clean and smooth and free from fouling organisms, such as barnacles, algae and molluscs. Therefore, they are coated with anti-fouling systems. During the 1960s, the chemical industry developed efficacious and cost-effective anti-fouling paints using metallic compounds, particularly the organotin compound tributyltin, TBT. By the 1970s most seagoing vessels had TBT paints on their hulls. During the 1960s the chemical industry developed efficacious and cost effective anti-fouling paints using metallic compounds, in particular, the organotin compound tributyltin – TBT. By the 1970s most seagoing vessels had TBT paints on their hulls.