Question 2158 Deck Safety

The correct answer is D) metacentric height. The abbreviation "GM" is used to represent the metacentric height, which is a measure of a ship's initial stability. The metacentric height is the vertical distance between the center of gravity and the metacenter of the ship, and it determines the vessel's ability to right itself when heeled over. A positive metacentric height indicates that the ship is stable, while a negative metacentric height indicates that the ship is unstable. The other options are incorrect because they represent different stability-related parameters: A) righting arm, B) height of the metacenter, and C) righting moment. These are related to, but distinct from, the metacentric height.