Exam Question

### (a) Hull Roughness Management
**1. Concept and Significance**
Hull roughness management is a critical aspect of vessel performance optimization, aimed at maintaining a hydrodynamically smooth underwater hull surface to minimize frictional resistance. Frictional resistance constitutes the largest component of a ship's total resistance, often accounting for 60-90% depending on the vessel's speed and form. An increase in hull roughness leads to a thicker turbulent boundary layer, causing a disproportionately large increase in drag and consequently, higher fuel consumption and greenhouse gas (GHG) emissions. The management of hull condition is a cornerstone of compliance with energy efficiency regulations such as the Energy Efficiency Existing Ship Index (EEXI) and the Carbon Intensity Indicator (CII).
**2. Causes of Hull Roughness**