🔍 Key Concepts

• KM (Metacentric Height Above Keel) – the distance from the keel (bottom of the ship) to the metacenter • KG (Center of Gravity Above Keel) – the distance from the keel to the ship’s center of gravity • GM (Metacentric Height) – the stability lever, calculated as GM = KM − KG

💭 Think About

• Think about what happens to GM when KG becomes numerically equal to KM: what does GM become? • How does the sign (positive, zero, or negative) and size of GM relate to a vessel’s ability to return to upright after a small heel? • Imagine gently heeling the vessel a few degrees: with this GM value, will the ship want to return upright, stay as is, or continue to heel?

✅ Before You Answer

• Calculate GM = KM − KG using the condition given in the question • Match GM > 0, GM = 0, and GM < 0 with the words: maximum, positive, neutral, and negative stability • Confirm which term properly describes a vessel whose righting moment for very small angles just disappears but does not yet become capsizing