🔍 Key Concepts

• Air gap on a jack-up unit (distance between the underside of the hull and the still water level) • How water depth and expected storm wave height influence minimum air gap • The importance of following the unit’s operating manual / design criteria for safe elevation

💭 Think About

• Think about why a jack-up like COASTAL DRILLER must have clearance above the highest expected wave crest, not just calm-water level. • In 200 feet of water, would you expect larger, smaller, or similar wave heights compared to shallow water, and how would that affect the needed air gap? • Compare the choices: which value gives a realistic safety margin between the sea surface (including waves) and the bottom of the hull for offshore operation?

✅ Before You Answer

• Check which option seems most consistent with a minimum safe clearance above storm waves, not fair-weather conditions. • Eliminate any air gaps that feel too small for offshore jack-up operations in 200 feet of water. • Remember that the air gap is chosen to prevent wave impact on the hull; verify which choice best reflects that safety need.