The main fleet base
Building the Navy’s Bases in World War II says the earliest advance-base shipments, among them Bora Bora and Efate, were laid out for one island at a time. Typical plans replaced that. Two fleet-base types were drawn. A LION was approximately the size of Pearl Harbor before the war. A CUB was about one-fourth of a LION.
The August 1942 allowance
The Logistics of Advance Bases, a Navy administrative history, prints a revised plan of 25 August 1942. LION totals in that plan, exclusive of flying and defense personnel, were 321 officers and 9,734 men. Inside that figure were five construction battalions, 110 officers and 2,908 men.
A 2017 article by Gina Nichols, archivist at the U.S. Navy Seabee Museum, describes a LION as 73 components, over 8,000 men, and 129,000 measurement tons of equipment and material. That headcount is the article’s. It is not the August 1942 allowance, which excludes flying and defense personnel and prints 9,734 men.
LION One
The same museum article says LION One was the first major unit to go to the Pacific under the functional-component system, in early 1943. The destination was Base Button, at Espiritu Santo in the New Hebrides. The command went out in five echelons and took three months to unload.