🔍 Key Concepts

• Center of gravity (G) vs center of buoyancy (B) in stability diagrams • Meaning of the metacenter (M) and how it is shown relative to G and B • What the righting arm (GZ) represents in a heeled vessel diagram

💭 Think About

• Look at which point in the diagram has the weight (downward) force line passing through it and ask yourself: is that usually G, B, M, or GZ? • Compare how the waterplane and underwater volume shift when the vessel heels: which labeled point tracks the geometric center of the underwater volume? • Consider which quantity is a distance or lever arm between two points, rather than being a point itself.

✅ Before You Answer

• Identify which symbol in the diagram is located on the line of action of weight (red arrow) rather than buoyant force. • Confirm that B is associated with the underwater volume and moves as the vessel heels, while G is fixed for a given loading condition. • Verify that GZ in textbook stability diagrams is usually shown as a horizontal distance (lever arm), not a single dot.