As Chief Engineer of an ocean going 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.

Watertight doors in subdivision bulkheads must remain closed during navigation to preserve subdivision integrity and prevent progressive flooding during a collision or grounding. They may only be opened temporarily for working the vessel under strict administrative control, remaining continuously ready for immediate closure.