🔍 Key Concepts

• Stability manual / operating manual limits for the specific unit (DEEP DRILLER) at survival draft • How vertical moments including free surface affect GM (metacentric height) and overall stability in a severe storm • Difference between normal operating limits and survival condition limits for vertical moments

💭 Think About

• Look at how "maximum vertical moments, including free surface moments" would be defined in the stability booklet or exam stability data for this specific rig – where in the data tables would that number usually appear? • Consider whether the survival draft condition normally allows higher or lower vertical moments than normal operating conditions, and why. • Think about which answer choice is most consistent with a clearly defined tabulated limit rather than a value derived from a calculation you would have to perform on the exam.

✅ Before You Answer

• Verify that you are using the correct condition table ("survival draft" / severe storm) from the DEEP DRILLER stability data, not the operating or transit condition. • Confirm that the figure you select is specified as "maximum allowable" total vertical moment including free surface, not just cargo or variable load moment alone. • Double-check that the units match exactly: ft‑tons and that free surface moments are explicitly included in the stated limit.