Fuel costs represent over half of a ship's operating costs; this can be even higher for large tankers and fast container ships. Therefore, many owners focus on a smoother hull, which can be achieved by construction in better steel quality, better welding techniques, better surface preparation and upgraded paint systems. Better communication aids and more fuel efficient engines have also minimized fuel consumption.
However, in terms of energy loss per unit area, propeller roughness significantly affects ships fuel consumption as well. Therefore, higher standards of propeller maintenance can be more cost effective than hull maintenance for many types of ships.
