🔍 Key Concepts

• Maximum allowable KG from a stability letter or table is based on the vessel’s displacement/draft and the environmental condition (normal vs. severe storm). • For a given draft, a more severe weather condition requires a lower maximum KG to ensure adequate GM (metacentric height) and stability margin. • You typically read this value from a KG vs. draft curve or table that has separate columns/curves for severe storm conditions.

💭 Think About

• Look at the stability data (or imagine the stability booklet): for a draft around 10.5 feet, how does the maximum KG change as weather criteria become more severe? • Between these answer choices, which values seem too high to be safe for a jack-up or similar offshore unit in a severe storm at that shallow draft? • Think about the relationship between higher KG and stability: does increasing KG make the vessel more or less stable, and which of these answers would still leave a good safety margin in a storm?

✅ Before You Answer

• Confirm that for severe storm criteria, the allowable KG is lower than for normal operating conditions at the same draft. • Check which answers are unrealistically high for a severe storm maximum KG at 10.5 feet of draft for a mobile offshore drilling unit. • Make sure you are thinking about maximum allowable KG, not actual KG — it’s the upper limit beyond which the unit would not meet stability criteria.