Your passenger vessel has departed port with 1,235 passengers on board for a 10 day voyage. What should be your ship's standard operating procedures regarding watertight hatches and doors?

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.

46 CFR 78.17-35 mandates that watertight doors in subdivision bulkheads remain closed during navigation. They may only be opened for essential vessel operations, provided they are immediately ready for closure. This maintains the vessel's subdivision integrity, which is critical for buoyancy and stability in the event of flooding.