Top Secret: US Naval Base At Ulithi Was For A Time The World’s Largest Naval Facility


On March 1945, the largest convoy of US Navy ships and personnel sailed from a base in the Pacific Ocean. Where was this base? This monumental force comprised of 106 destroyers, 29 aircraft carriers, 15 battleships, and 23 cruisers and you can just imagine how many support personnel was required.

Ulithi is 1300 miles south of Japan, specifically Tokyo, 850 miles east of the Philippines, and 360 miles southwest of Guam. It is a classic Pacific atoll with coral reef, palm trees, and white sand. It had depths ranging 80 to 100 feet; suitable depths for anchoring the huge naval ships. It was the only fitting haven for 800 miles where the US Navy could anchor its ships. The coral reef is approximately 20 miles long and 10 miles wide, and there are over 30 little islands rising slightly above sea level, the largest only half a square mile in area.

September 1944 – the US Navy landed and found 400 natives and three enemy soldiers residing there. The natives were settled on four larger islands, Sorlen, Falalop, Asor, and Mogmog and they were all moved to a smaller island, Fassarai.

A 3,500-foot airstrip was built at Falalop; it was just barely wide enough to handle the Douglas DC-3s and the R5C Commandos that would arrive from Guam. On a weekly basis 4565 sacks of mail, 262,251 pounds of air freight, and 1269 passengers would land on this airstrip.

Mogmog was the location for recreation. What was next? Where were they going to locate the actual Naval Base?

The Commodore, who survived Pearl Harbor, created the phenomenal mobile service command that allowed the US Navy to head for Japan in great strides. Instead of utilizing the costly and time-consuming alternative of seizing hundreds of small islands on which to build a series of land bases and airstrips.

Many refrigerated and food supply ships operated by a three-tier team:

  • Ship # 1 docked at Ulithi was emptied of its supplies and then headed out to relieve
  • Ship # 2 which was at the rear dock being loaded with more supplies, while
  • Ship # 3 was on the way to Ulithi to relieve Ship # 1.

More than half the ships had to be towed to actually dock. Some of them remained docked to serve as inventory warehouses as the recurring system of load, unload, and distribute provided food and stores for the base and personnel.


US Navy 1944 berthing chart for the Northern Anchorage of the Ulithi Lagoon, Caroline Islands

The troop landings at Okinawa were not documented well, but in actuality, they involved more ships, supplies, and men, – including 600,000 gallons of fuel oil, 1,500 freight cars of ammunition, and enough food to provide a huge population with three meals per day for fifteen consecutive days. Some of the smaller ships provided numerous services, such as the ice cream skiff – it made 500 gallons each shift and the USS ABATAN, which looked like a big tanker but was really distilling fresh water, as well as baking pies and bread.

They also had additional men, and carried the mail and medical supplies, and began to supply orders for spare parts to the mechanics at Ulithi. When the Leyte Gulf was secured by the Allies, the floating base from Ulithi moved on.

Just a few short months ago it had a temporary population of a large US city and was the ruler of the Pacific. Now it was reduced to little more than a tanker depot. As before the war, it became a lonely, quiet coral island.

The atoll

The U.S. Navy destroyer minelayer USS Shannon (DM-25) steams past task forces gathering for the Okinawa Operation at Ulithis Atoll, circa in March 1945.
The ships in the near background include the light cruisers USS Flint (CL-97), in left center, and USS Miami (CL-89), at right. Three Essex-class aircraft carriers are anchored in the middle distance. USS Enterprise (CV-6) is at the far left.

Ulithi Atoll north anchorage and Sorlen Island, late 1944


Ships of the 3rd fleet Ulithi December 1944

U.S. Navy 3rd Fleet warships and auxiliaries anchored at Ulithi Atoll, Caroline Islands, shortly after the Battle of Leyte Gulf, on 6 November 1944. The battleships USS New Jersey (BB-62) and USS Iowa (BB-61) are in the center and at right. Five Essex-class carriers are moored in line in the upper center.


Ships of the 3rd fleet Ulithi December 1944


Ships of the 5th fleet Ulithi


Ulithi January 1945


The U.S. Navy aircraft carriers USS Wasp (CV-18), USS Yorktown (CV-10), USS Hornet (CV-12), and USS Hancock (CV-19) anchored in Ulithi Atoll as seen from the carrier USS Ticonderoga (CV-14). On Ticonderoga´s deck are 20 Grumman F6F Hellcat and a single Grumman TBF Avenger of Carrier Air Group 80 (CVG-80).

The U.S. Navy battleship USS Iowa at a forward anchorage as viewed from the aircraft carrier USS Intrepid (CV-11). A cargo ship is moored aft of Iowa, and a converted flush deck destroyer ahead. The photo was probably taken at Majuro or Ulithi Atoll. Note Iowa´s camouflage measure 32, design 1B.

Ships of the U.S. Navy Pacific fleet anchored at Ulithi Atoll, Caroline Islands, circa 7-10 February 1945, just prior to the Iwo Jima operation. The aircraft carrier USS Saratoga (CV-3) is in the right middle distance. There are at least eight Essex-class carriers present.


Ulithi Anchorage


U.S. Third Fleet aircraft carriers at anchor in Ulithi Atoll, 8 December 1944, during a break from operations in the Philippines area. The carriers are (from front to back): USS Wasp (CV-18), USS Yorktown (CV-10), USS Hornet (CV-12), USS Hancock (CV-19) and USS Ticonderoga (CV-14). Wasp, Yorktown and Ticonderoga are all painted in camouflage Measure 33, Design 10a. The other Essex-class carrier painted in sea blue Measure 21 is USS Lexington (CV-16).


Murderer’s Row


USS North Carolina at Ulithi


Ulithi Anchorage


Ulithi Anchorage


USS SOUTH DAKOTA foreground and USS NEW JERSEY in the background in Ulithi Atoll. 8 Dec. 1944


The USS South Dakota in Ulithi Atoll in December 1944. The hospital ship in the background, identified on the photo as the USS Solace, is instead almost certainly the USS Samaritan.

The U.S. Navy destroyer tender USS Prairie (AD-15) at Ulithi Atoll, in 1945. Alongside are three Allen M. Sumner-class destroyers and a Fletcher-class destroyer.

The U.S. Navy Atlanta-class cruiser USS Flint (CL-97), probably at Ulithi Atoll, circa late March 1945, as the U.S. Fifth Fleet was departing for the Okinawa operation. Flint´s camouflage is Measure 33, Design 22d. Note the two Essex-class carriers in the background, the left one probably being USS Bon Homme Richard (CV-31). USS Tennessee (BB-43) is visible in the background (her sister ship California was under repair at Puget Sound at that time).


USS Essex underway from Ulithi CV-9 – 10 Feb 1945


Officers of Bombing Squadron (VB) 4 pictured with an SB2C Helldiver on the flight deck of the carrier Essex (CV 9) at Ulithi Atoll.

R&R Island


R&R on Mog-Mog Island in Ulithi Atoll


Mog-Mog liberty c 1944


Mog-Mog liberty c 1944


Mog-Mog liberty c 1944


Mog-Mog liberty c 1944


Mog-Mog O-club


Mog-Mog liberty


Mog-Mog baseball


Shipmates from USS ESSEX CV-9 enjoy liberty at the beach in Ulithi Atoll December 1944


Mog-Mog beach liberty


Ulithi R&R


Ulithi R&R


Mail call Ulithi c 1944


Mog-Mog liberty


Mog-Mog liberty


F6F-5N Hellcat aircraft of VMF(N)-541, MAG-45, are on the ground at Falalop Island, Ulithi Atoll 1945


R4D Aircraft Used as a Projection Room for Movies, Ulithi, 1944


Corsair at Ulithi Atoll strip