With regard to the opening and closing of watertight integrity appliances not fitted with a remote operating control or alarm system, what must the Master or person in charge of a MODU enter in the logbook?

Correct Answer: Option C — The reason for opening or closing each appliance

46 CFR 109.203 requires that the reason for opening or closing watertight integrity appliances, which lack remote controls or alarms, be entered in the logbook. This practice ensures that the status of the unit's watertight integrity is always known and documented for stability and safety.