🔍 Key Concepts

• Metacentric height (GM) and what it says about stability and roll period • Difference between a stiff vessel and a tender vessel in terms of motion in a seaway • Relationship between GZ (righting arm) and how quickly a vessel returns upright

💭 Think About

• Think about whether a vessel that rolls slowly and gently has a long or short roll period, and what that implies about GM. • Ask yourself: does a large righting arm make a vessel snap back upright quickly, or move slowly and easily? • Consider what happens when the center of gravity is high versus low: which condition leads to quick, jerky motion and which to slow, easy motion?

✅ Before You Answer

• Be clear on whether a large GM makes the roll period longer or shorter. • Review the definitions of stiff and tender vessels and match them with fast or slow rolling. • Check which option corresponds to a condition that produces slow, easy rolling rather than quick, snappy motion.