Your vessel is damaged and listing to port. The rolling period is long, and the vessel will occasionally assume a starboard list. Which action should you take FIRST?

Correct Answer: Option D — Press up a slack centerline double bottom tank

A long rolling period and occasional lurching to starboard indicate dangerously low or negative GM compounded by free surface. Pressing up a slack centerline double-bottom tank eliminates free surface, lowers the vertical center of gravity, and restores positive stability.