🔍 Key Concepts

• Free surface effect and how it impacts a vessel’s metacentric height (GM) • How displacement (Δ) appears in the standard free surface correction formula • Relationship between tank geometry (moment of inertia of the liquid surface) and the ship’s overall displacement

💭 Think About

• Think about the standard formula for free surface correction (FSC). Where does the ship’s displacement appear in that formula—numerator or denominator? • If the ship becomes heavier (greater displacement) but the tank and liquid surface area stay the same, what happens to the size of the correction per tank? • Is the correction more serious on a light ship or a loaded ship with the same slack tank condition?

✅ Before You Answer

• Verify how FSC is calculated: it involves the moment of inertia of the free surface divided by the ship’s displacement (Δ). • Confirm whether the tank dimensions and liquid density are assumed constant when you change displacement in this question. • Check if the relationship is inverse or direct between displacement and the numerical value of the free surface correction.