What is "ballast" used for in ships?

Ballast is an essential component in ship design and operation, primarily used to provide stability and control buoyancy. When a vessel is laden with cargo, ballast helps lower the center of gravity, enhancing the ship's stability in various sea conditions. It can be water, solid material, or other substances placed in the ship's bottom or other designated compartments. Proper ballast adjustment is crucial, especially when loading or unloading cargo, to ensure the ship maintains an even keel and prevent capsizing or excessive rolling in waves.

In this context, options related to storing fuel or generating electrical power do not pertain to the role of ballast. While ships do require electrical power for various functions, ballast does not serve this purpose. Similarly, while ships transport cargo, ballast is not intended for cargo storage but rather for stabilizing the vessel. Thus, the primary and correct function of ballast in ships is to provide stability and control buoyancy.