Which of the following describes the primary purpose of a ship's ballast system?

The primary purpose of a ship's ballast system is to adjust and maintain stability and trim. Ballast helps to lower the center of gravity of the ship, which enhances its stability in various sea conditions. By manipulating the amount of ballast water taken on or discharged, the ship can maintain an optimal trim, ensuring that the hull is positioned correctly in the water for efficient performance.

Stability is critical for safety and operational efficiency, especially during rough weather or when the ship undergoes significant changes in weight or load distribution. Without a properly functioning ballast system, a vessel may become unmanageable and susceptible to capsizing. Therefore, the ballast system is a fundamental aspect of maritime engineering that directly influences a ship's seaworthiness and safety.