This standard defines the methodology of measuring hull roughness of vessels in dry-dock. This standard does not mention the type of instrument/gauge for such measurements. This standard is limited to a methodology--no interpretation of the results obtained is presented. One of the factors affecting a ship's performance and fuel consumption is the roughness of its foul-free underwater hull. The condition and type of paint system used may have a major influence on hull roughness and ship performance. Hull roughness has a major impact on vessel fuel efficiency and exhaust emissions. This standard focuses on the mechanical roughness of the hull. A roughness survey is used to arrive at a measured value to determine the added friction drag caused by the roughened, but foul-free, coated surface.