On the hull of a ship can grow full of crustaceans, algae and other roughnesses such as rust formation. This increases the frictional resistance of the ship, with the result that extra energy (fuel) consumption is required for the ship’s propulsion to overcome that resistance. To prevent this fouling, applying a special coating to the ship’s side can considerably limit/prevent this.
The photos below clearly show that the wall of the ship is free of algae (fouling), this is due to the special coating (anti-fouling). The white numbers of the depth markings are of a different type of paint which do not have this algae-free property.
