As chief engineer of an oceangoing passenger vessel, it is important to know the effect of trim and stability of your ship in the event of damage to a compartment. To minimize the impact of flooding in the event of a grounding, what should be your ship's safe practice regarding watertight doors and hatches?

Correct Answer: Option A — All watertight doors in subdivision bulkheads shall be kept closed during navigation except when necessarily opened for working of the vessel, and in such cases they shall always be ready to be immediately closed.

Per 46 CFR 77.05-1, watertight doors must remain closed during navigation to maintain subdivision integrity. They may only be opened for essential vessel operations, provided they are manned or immediately closable. This practice ensures the vessel's damage stability remains within design parameters, preventing progressive flooding during a grounding or hull breach.