The dark waters of the Gulf of Mexico were quickly covered in frothy firefighting foam as they flooded into the well deck of this 25,000-ton ship. Although the vessel’s rolls were gentle in the heat of a summer evening, the water — looking for all the world like a giant bubble bath — sloshed dramatically back and forth, splashing almost to the full three-deck height of the space. Watching intently were members of the Navy’s Board of Inspection and Survey, who were looking to see if the brand-new Anchorage could successfully ballast down and flood the deck in 15 minutes or less…