What does the term "KG" refer to in the context of a vessel?

The term "KG" in the context of a vessel refers to the vertical distance from the keel to the center of gravity of the lightship. It is an important parameter in stability calculations, as it helps determine how the weight of the vessel is distributed and its overall stability in the water.

Understanding KG is essential for assessing a ship's stability since a higher center of gravity can lead to a tendency for the vessel to heel more easily under external forces, which can affect its safety and performance. This measurement is critical when making decisions about loading, ballast, and other factors that impact the vessel's stability.

In contrast, the total weight of the ship's cargo, the hull's overall height from the keel, and the ship's length overall refer to other aspects of the vessel's characteristics, but they do not define KG. Therefore, the focus on the center of gravity of the lightship is what makes this choice the correct interpretation of the term "KG."