🔍 Key Concepts

• Free surface effect and how it impacts vessel or MODU stability • Purpose and normal operating level of fuel oil day tanks • Safe and legal methods of dealing with fuel in heavy weather

💭 Think About

• How does a liquid in a partially filled tank affect stability compared to a full or empty tank? • In heavy weather, do you want to increase or decrease the free surface effect? What tank condition best achieves that? • Which choices describe actions that would actually be allowed and make sense from a safety and pollution-prevention standpoint?

✅ Before You Answer

• Identify which option reduces free surface effect rather than increasing it • Eliminate any option that would clearly violate pollution prevention rules (think MARPOL / oil discharge rules) • Ask whether the selected option would realistically improve the MODU’s stability and safety in heavy weather