SS Anthony F. Lucas—a Liberty ship—was laid down under a Maritime Commission contract (MCE hull 2422) on 29 October 1943 at Houston, Texas, by the Todd-Houston Shipbuilding Corp.; acquired by the Navy under a bareboat charter on 2 November 1943; renamed Zaniah and classified as a cargo ship, AK-120, on 13 November; launched on 12 December; sponsored by Mrs. LeRoy Bembry; and accepted by the Navy and commissioned on 22 December 1943, for ferrying to the Alabama Drydock and Shipbuilding Company's yard at Mobile, Alabama, for conversion.

Zaniah underwent further conversion at the Pearl Harbor Navy Yard—receiving additional office spaces and living quarters to accommodate the staff of a fleet service division.

Zaniah soon shifted to the Solomons, providing water and repair services at Purvis Bay, Florida Island, from the day of her arrival, Washington's Birthday 1945.

The first ship of her type in the area, she arrived at a critical time, as her commanding officer wrote: "when damage was at its height and repair facilities and personnel were scarce."

Zaniah shifted to Buckner Bay on 10 July and performed her services as a repair and water-distilling ship through the end of the war with Japan in mid-August.

She suffered some damage in a typhoon which struck the Fleet's anchorage on 16 September, when Ocelot (IX-110) dragged her anchor in the tempest and brushed heavily against Zaniah, smashing a motor whaleboat and demolishing some bulwarks and stanchions on board the repair vessel.

Decommissioned at Pearl Harbor on 29 April 1946, Zaniah was towed to the west coast; reached Suisun Bay, California, on 14 May 1947; and was turned over to the Maritime Commission the following day.