Vessels subject to SOLAS are required to keep watertight doors closed while the vessel is navigating. Which of the following is an exception to this requirement?

Correct Answer: Option D — any door stated in the ship's stability book as being permitted to remain open

SOLAS Chapter II-1, Regulation 22 requires watertight doors to be kept closed during navigation. An exception is made for doors that are specifically permitted to remain open by the vessel's approved stability information, provided they can be closed immediately if necessary to maintain watertight integrity.