Glossary Term
Antifouling Paint
Antifouling paint is the underwater coating applied to a yacht’s hull and niche areas to control the attachment of marine organisms. In yacht use, the term usually refers to the final submerged coating system selected to limit slime, weed, and hard fouling during service. Its purpose is functional as much as protective: a cleaner underwater surface preserves speed, efficiency, and handling while reducing the rate at which roughness builds up between dockings.
The regulatory framework behind the term comes from the IMO Anti-Fouling Systems Convention. That convention prohibits harmful organotin compounds in anti-fouling systems and provides a mechanism to control other harmful substances in the future. IMO also notes that anti-fouling paints are used to prevent organisms attaching to the hull, since fouling slows the ship and increases fuel consumption.
For yachts, coating choice depends on operating profile as much as on product type. Time at anchor, warm-water lay-up, service speed, cleaning regime, and the condition of the substrate all influence how well the paint will perform. The coating only works properly when it sits over the correct preparation and build system, which is why antifouling renewal usually belongs inside a wider painting package.
When antifouling performance drops, the result is not limited to a dirty hull. Fouling increases drag, shifts the speed-power relationship, and can bring earlier cleaning, higher fuel burn, and a less predictable interval to the next docking.