Question 2125 Deck Safety

The correct answer is A) negative GM. A negative GM (metacentric height) means the vessel's center of gravity is above the metacenter, causing the vessel to be unstable and list with equal readiness to either side. This instability is the most likely cause of a vessel listing equally to both sides. The other options are incorrect - excessive freeboard (B) would not cause equal listing, off-center weight (C) would cause the vessel to list in the direction of the off-center weight, and pocketing of free surface (D) would cause the vessel to list in the direction of the free surface.