What does the term displacement refer to in a vessel?

Displacement in the context of a vessel specifically refers to the weight of the water that the vessel displaces when it is afloat. This is a direct reflection of the weight of the vessel itself when it is fully loaded or in its operating condition. When a ship is in water, it pushes out a volume of water equal to its weight due to the principle of buoyancy established by Archimedes.

The correct interpretation is that displacement is measured in tons, which indicates how much water is pushed aside by the vessel. This understanding is crucial for marine navigation, stability calculations, and ensuring compliance with safety regulations.

In contrast, the other options touch on related concepts such as the volume of water displaced, weight, and load capacity, but they do not accurately capture the definition of displacement as it relates to the measurement in tons that is primarily of interest in this context.