Answer
Here is a comprehensive breakdown structured for a thorough technical review.
1. Fundamental Principles
The stability of a vessel depends on the interaction of three primary points:
Center of Gravity (G): The point through which the total downward force of the ship's weight acts. Its position depends on the distribution of weights (cargo, fuel, ballast) on board.
Center of Buoyancy (B): The geometric center of the ship's underwater volume. It is the point through which the upward force of buoyancy acts. As the ship heels, the underwater shape changes, and 'B' moves.
Metacenter (M): The point of intersection between the vertical line through the initial center of buoyancy and the vertical line through the new center of buoyancy when the ship is slightly heeled.
When a ship heels, the separation between the vertical downward line of gravity and the upward line of buoyancy creates a Righting Lever (GZ). The resulting Righting Moment (RM) is what pushes the ship back upright, calculated as:
RM=Δ×GZ
(Where Δ is the ship's displacement)