Exam Question

In the context of stringent environmental regulations such as the Energy Efficiency Existing Ship Index (EEXI) and the Carbon Intensity Indicator (CII), ship operators are increasingly focusing on improving hydrodynamic efficiency to reduce fuel consumption and emissions. Hull and propeller maintenance are paramount in this effort, as they directly address the frictional and form drag components of a vessel's total resistance.
### (a) Hull Roughness Management
**1. Objective:**
The primary objective is to maintain the smoothest possible hull surface to minimize frictional resistance. A ship's hull moving through water creates a boundary layer. A smooth hull promotes a thinner laminar sub-layer, reducing the turbulent shear stresses that create drag. Increased roughness thickens this boundary layer, significantly increasing frictional resistance and thus the required propulsion power.