How do ballast tanks work?

Ballast tanks are compartments in ships or submarines that can be filled with water or emptied to control buoyancy and stability. When water is pumped into these tanks, the vessel's weight increases, allowing it to sink lower in the water, enhancing stability in rough seas or during loading. Conversely, when the water is pumped out, the vessel becomes lighter and rises, making it easier to maneuver or surface. This system is crucial for maintaining safe and efficient operation, especially in varying sea conditions.