🔍 Key Concepts

• Angle of loll vs. a normal list (what does a long rolling period and alternately heeling to both sides tell you about GM and stability?) • Effect of free surface and slack tanks on GM (how do slack tanks change stability?) • Difference between improving GM first (making the ship more stable overall) and correcting the list sideways (moving weight port–starboard)

💭 Think About

• If a ship has a long rolling period and sometimes lists to the opposite side, is this more likely a simple off-center weight problem, or a GM (overall stability) problem such as an angle of loll? • When the vessel may be at an angle of loll, which should be done first: (1) try to stand the ship up by moving weight sideways, or (2) try to make GM positive and larger by moving weight vertically (especially low in the ship)? • Look at each option and ask: does this action reduce free surface and/or put weight low and near the centerline, or does it risk increasing off-center weight and making heel worse?

✅ Before You Answer

• Identify which options add weight low and on/near the centerline versus those that move weight sideways or remove low weight • Check which choice reduces or avoids slack tanks/free surface instead of creating more slack or off-center tanks • Before choosing, ask: "If this were an angle of loll, which action is recommended FIRST in stability guidance—correct GM or correct list?"