🔍 Key Concepts

• GM (metacentric height) and what it indicates about initial stability • Relationship between GM size and rolling period (slow vs quick roll) • Effect of small GM on how a vessel behaves in heavy seas (roll angle and timing)

💭 Think About

• Think about what happens to a ship’s roll when stability is low: does it snap back quickly or more slowly? • Which condition (small or large GM) is more likely to produce large, slow rolls that can match the wave period? • In heavy weather, would a vessel with small GM tend to roll more or less, and more smoothly or more jerkily?

✅ Before You Answer

• Recall that large GM = stiff vessel (quick, jerky roll) and small GM = tender vessel (slow, easy roll). Match each choice to that idea. • Check which choice talks about rolling period and decide whether small GM means short or long period. • Identify which option involves synchronous rolling, and think: does that happen more easily with slow, large-amplitude rolls or quick, small-amplitude rolls?