🔍 Key Concepts

• Center of gravity (G) vs center of buoyancy (B) and how each one moves when a vessel heels or rolls • Difference between movement of the ship relative to G and actual movement of G • Effect of no shifting or moving weights on the position of the vessel's center of gravity

💭 Think About

• When a vessel rolls to starboard, does the structure of the ship and its internal weights actually change location inside the ship, or does the ship simply change its orientation in the water? • Which point (G or B) is affected by the change in underwater volume shape when the vessel heels, and which one only changes if weights shift or are added/removed? • Think about a simple rigid object, like a solid steel box with no loose weights inside. If you tip it, what happens to its center of gravity relative to the box itself?

✅ Before You Answer

• Confirm the definition: Center of gravity (G) is the point through which the total weight of the vessel acts and only changes if weights are added, removed, or shifted • Confirm that a pure roll or heel without shifting cargo means there are no relative internal weight movements • Distinguish between G’s position within the vessel and how that point appears to move relative to the water surface or Earth when the vessel tilts