Your vessel is discharging containers from the main deck with the ship's cranes. Which of the following must be taken into account when calculating the center of gravity as the containers are discharged?

Correct Answer: Option A — the vertical distance from the main deck plus the vertical distance to the head of the boom

When using a boom to lift cargo, the weight is effectively suspended from the head of the boom. Therefore, the vertical center of gravity of the system shifts to the height of the boom head. Stability calculations must account for this elevated center of gravity to prevent a dangerous reduction in GM.