If a vessel is to be laid up for an extended period of time with minimal utilities provided where freezing is not a concern; boilers may be laid up wet. What statement concerning wet boiler lay-up is true?

Correct Answer: Option C — The boiler should be completely filled with dearated and chemically treated water until water issues from the atmospheric vent.

Wet lay-up requires the boiler to be completely filled to exclude oxygen, preventing corrosion. Using deaerated, chemically treated water ensures the internal surfaces are protected from pitting. Filling until water issues from the atmospheric vent confirms all air pockets are removed, which is critical for long-term preservation of waterside surfaces.