🔍 Key Concepts

• GMT (transverse metacentric height) and what it represents for stability • Relationship between righting moment and angle of inclination when GMT changes • Behavior of a Mobile Offshore Drilling Unit (MODU) when its stability reduces but a heeling moment remains the same

💭 Think About

• If the heeling force stays the same but GMT (initial stability) gets smaller, what happens to the size of the righting arm needed to balance that heel? • Think about whether a smaller GMT makes the vessel "stiffer" (returns upright quickly with small angles) or "tender" (larger angles for the same heeling moment). • How does a reduction in GMT affect the angle at which the righting moment equals the heeling moment?

✅ Before You Answer

• Recall that GMT is directly related to the initial slope of the righting arm (GZ) curve at small angles. • Consider whether a lower GMT means the same heeling moment is balanced at a larger or smaller angle of heel. • Be sure you are not confusing angle of loll (which occurs when G is above M) with normal heel due to a steady heeling moment.