🔍 Key Concepts

• Angle of loll and what it means about a ship’s initial stability (GM) • Relationship between GZ (righting arm) and list/loll • How the GZ curve behaves when a vessel is initially unstable (negative GM)

💭 Think About

• Think about what causes an angle of loll: is the ship initially stable or unstable when upright? What does that say about GM? • At the exact angle of loll, is the ship trying to roll back upright or stay where it is? What does that imply about the size and sign of the righting arm GZ? • Sketch (mentally or on paper) a simple GZ curve for a vessel with negative GM. What happens to GZ at the angle(s) where the ship comes to rest?

✅ Before You Answer

• Be clear on the difference between list (caused by off-center weight) and loll (caused by unstable upright condition). • Focus on the sign of GZ (righting arm) at the angle where the ship just stops rolling due to instability: is there a restoring or overturning moment? • Verify how textbooks define angle of loll in relation to the point where the GZ curve crosses the baseline.