Hull Coating
Hull Coating is the multi-layer paint system applied to the underwater and topside steel of a ship. Below the waterline it does two jobs: an anticorrosive primer protects the steel, and an antifouling topcoat — often a self-polishing copolymer or a silicone foul-release coating — prevents barnacles, weed and slime from building up on the hull.
Coatings are renewed at dry-docking after the hull is high-pressure washed and abrasive blasted back to bare or sound steel. The choice and condition of the antifouling directly affect fuel consumption, because marine growth increases hull friction and drag.
A fouled or degraded hull coating quietly burns fuel — even a thin slime layer measurably raises drag and consumption, and heavy fouling can add double-digit percentages. Coating scope is one of the largest cost lines in a docking, and the coating choice is now also a decarbonisation and emissions decision, not just a maintenance one.
How does hull coating affect fuel consumption?
Marine growth and a rough or damaged coating increase the friction between hull and water, raising resistance and fuel burn. A clean, smooth antifouling keeps consumption — and emissions — down between dockings.