Ulithi (Yapese: Wulthiy, Yulthiy, or Wugöy) is an atoll in the
Caroline Islands of the western Pacific Ocean, about 191 km (103
nautical miles) east of Yap. It consists of 40 islets totalling
4.5 km2 (1.7 sq mi), surrounding a lagoon about
36 km (22 mi) long and up to 24 km (15 mi)
wide—at 548 km2 (212 sq mi) one of the largest in the
world. It is administered by the state of
Yap in the Federated States
of Micronesia. Ulithi's population was 773 in 2000. There are four
inhabited islands on
Ulithi Atoll. They are Falalop (Ulithian:
Fl'aalop), Asor (Yasor), Mogmog (Mwagmwog), and Fedarai (Fedraey).
Falalop is the most accessible with an air strip, a small resort
hotel, gas dealership, store and one of three public high schools in
Yap state. Mogmog is the seat of the high chief of
each island has its own chief. Other important islands are Losiap
(Ulithian: L'oosiyep), Sorlen (Sohl'oay), and Potangeras
The atoll is in the westernmost of the Caroline Islands, 360 miles
(580 km) southwest of Guam, 850 miles (1,370 km) east of the
Philippines and 1,300 miles (2,100 km) south of Tokyo. It is a
typical volcanic atoll, with a coral reef, white sand beaches and palm
trees. Ulithi's forty small islands barely rise above the sea, with
the largest being only one-half square mile (1.3 square kilometres) in
area. However the reef runs roughly twenty miles (32 kilometres) north
and south, by ten miles (16 kilometres) across, enclosing a vast
anchorage with an average depth of 80 to 100 feet
Ulithi was a major staging area for the U.S. Navy in the final year of
the Second World War. Several sunken warships rest at the bottom of
Ulithi lagoon, including the USS Mississinewa (AO-59), a
fleet oiler which sank fully loaded. The sunken tanker was found
to be seeping oil into the lagoon. The
United States Navy
United States Navy responded,
locating the tanker, tapping her storage tanks, and pumped off her
oil. The cleanup operation was completed in February 2003.
The atoll offers good fishing and diving, though recent typhoons have
eroded some of the reefs.
Census records can be misleading because population can fluctuate
during the year because it is common for Ulithians to leave for work
or school abroad and to return. This is particularly true during
festive times like the Outer Island High School graduation ceremony,
when the population can increase considerably. Additionally, during
events like weddings and funerals, Yasor's population may double.
Electricity is now available on some islands, and the advent of video
players and cell phones have brought a touch of the outside world to
this very isolated atoll. Occasional diving and adventure tours visit
Ulithi from Yap.
Sketch by Walter Allan Finlayson: Officer’s Hut on Mog Mog Island,
ULITHI, May 1945 WWII
1.1 Second World War
5 External links
The first European to find
Ulithi was the Portuguese navigator Diego
da Rocha, for four months in 1525. Its visit was recorded by
Spanish navigator Álvaro de Saavedra on board the ship Florida on 1
January 1528. He named them Islas de los Reyes (Islands of the Three
Wise Kings in Spanish) because of the sighting happening on the eve of
Epiphany. It was later charted by the Spaniards as Islas de los
Garbanzos (Chickpeas Islands in Spanish). It was also visited by
the Spanish expedition of
Ruy López de Villalobos on 26 January
1543. It remained isolated until visited and explored in detail
by Captain Don Bernardo de Egoy in 1712, and later visited by Spanish
Jesuit missionaries led by Juan Antonio Cantova together with a group
of 12 Spanish soldiers in 1731.
Germany purchased the islands from Spain in 1899. They were occupied
in 1914 by
Japan at the outset of the First World War.
them in 1920 as a League of Nations mandate.
Second World War
Sorlen Island looking into the north anchorage of
Ulithi atoll, 1945.
Early in the Second World War, the Japanese had established a radio
and weather station on
Ulithi and had occasionally used the lagoon as
an anchorage, but had abandoned it by 1944. As the operations of the
US Navy moved west across the Pacific, the Navy required a more
forward base for its operations.
Ulithi was perfectly positioned to act as a staging area for the US
Navy's western Pacific operations. The anchorage was large and
well situated, but there were no port facilities to repair ships or
re-supply the fleet.
U.S. naval forces including carriers in the distance at anchor in
Ulithi, March 1945
On September 23, 1944, a regiment of the US Army's 81st Division
landed unopposed, followed a few days later by a battalion of
Seabees. The survey ship USS Sumner (AGS-5) examined the
lagoon and reported it capable of holding 700 vessels—a capacity
greater than either
Majuro or Pearl Harbor.
The US Navy transferred the local islanders to the island of Fedarai
for the duration of the hostilities. Arriving next was Service
Squadron 10, termed by Admiral Nimitz as his "secret weapon". Its
commanding officer Commodore Worrall R. Carter devised the mobile
service force that made it possible for the Navy to convert
the secret distant Pacific base used during the major naval operations
undertaken late in the war, including Leyte Gulf and the invasion of
Okinawa. Service Squadron 10 converted the lagoon into a serviceable
naval station, creating repair facilities and re-supply facilities
thousands of miles away from an actual naval port. Pontoon piers of a
new design were built at Ulithi, each consisting of the
4-by-12-pontoon sections, filled with sand and gravel, and then sunk.
The pontoons were anchored in place by guy ropes to deadmen on shore,
and by iron rods driven into the coral. Connecting tie pieces ran
across the tops of the pontoons to hold them together into a pier.
Despite extremely heavy weather on several occasions these pontoon
piers stood up remarkably well. They gave extensive service, with
little requirement for repairs. Piers of this type were also installed
by the 51st Battalion to be used as aviation-gasoline mooring piers
near the main airfield on Falalop.
USS Iowa at a floating drydock at Ulithi
Within a month of the occupation of Ulithi, a complete floating base
was in operation. Six thousand ship fitters, artificers, welders,
carpenters and electricians arrived aboard repair ships, destroyer
tenders, and floating dry docks. The USS Ajax (AR-6) had an
air-conditioned optical shop and a metal fabrication shop with a
supply of base metals from which she could make any alloy to form any
part needed. The USS Abatan (AW-4), which looked like a big
tanker, distilled fresh water and baked bread and pies. The ice cream
barge made 500 gallons a shift. The dry docks towed to
large enough to lift dry a 45,000 ton battleship. The small island
of Mog Mog became a rest and recreation site for sailors.
Fleet oilers sortied from
Ulithi to meet the task forces at sea,
refueling the warships a short distance from their combat operational
areas. The result was something never seen before: a vast floating
service station enabling the entire Pacific fleet to operate
indefinitely at unprecedented distances from its mainland bases.
Ulithi was as far away from the US Naval base at San Francisco as San
Francisco was from London, England. The Japanese had considered that
the vastness of the
Pacific Ocean would make it very difficult for the
US to sustain operations in the western Pacific. With the
base to refit, repair and resupply, many ships were able to deploy and
operate in the western Pacific for a year or more without returning to
the Naval base at Pearl Harbor.
The Japanese had built an airstrip on Falalop. It was expanded and
resurfaced, the runway running the full width of the island. The east
end of the strip was extended approximately twenty feet (6.1 metres)
past the natural shoreline. A number of small strips for light
aircraft were built on several of the smaller islands. The Seabees
completed a fleet recreation center at Mog Mog island that could
accommodate 8,000 men and 1,000 officers daily. A 1,200-seat theatre,
including a 25-by-40-foot stage with a
Quonset hut roof was completed
in 20 days. At the same time, a 500-seat chapel was built. A number of
the larger islands were used both as bases to support naval vessels
and facilities within the lagoon.
A Japanese submarine carrying kaiten to their deployment.
USS Mississinewa burns while sinking following an attack by Japanese
The Japanese still held Yap. Early after the US occupation they
mounted a number of attacks but caused no damage to the Seabees
working on the islands.
On 20 November 1944 the
Ulithi harbor was attacked by Japanese kaiten
manned torpedoes launched from two nearby submarines. The destroyer
USS Case (DD-370) rammed one in the early morning hours. At
5:47 the fleet oiler USS Mississinewa (AO-59), at anchor in
the harbor, was struck and sunk. Destroyers began dropping depth
charges throughout the anchorage. After the war Japanese naval
officers said that two tender submarines, each carrying four manned
torpedoes, had been sent to attack the fleet at Ulithi. Three of the
suicide torpedoes were unable to launch due to mechanical problems and
another ran aground on the reef. Two did make it into the lagoon, one
of which sank the USS Mississinewa. A second kaiten attack in January
1945 was foiled when the I-48 was sunk by the destroyer escort
USS Conklin (DE-439). None of the 122 men aboard the
Japanese submarine survived.
The USS Randolph undergoing repairs following a kamikaze attack at
On March 11, 1945, in a mission known as Operation Tan No. 2, several
long range aircraft flying from southern
Japan attempted a nighttime
kamikaze attack on the naval base. One struck the Essex-class
aircraft carrier USS Randolph (CV-15), which had left a
cargo light on despite the black out. The plane struck over the stern
starboard quarter, damaging the flight deck and killing a number of
crewmen. Another crashed on Sorlen Island, having perhaps mistaken
a signal tower there for the superstructure of an aircraft
By March 13 there were 647 ships at anchor at Ulithi, and with the
arrival of amphibious forces staging for the invasion of Okinawa the
number of ships at anchor peaked at 722.
In late June 1945, the Japanese aircraft-launching super submarines
I-400 and I-401 were diverted from their planned attack on the Panama
Canal to attack
Ulithi Atoll. However, their mission was interrupted
by the destruction of Nagasaki and Hiroshima, followed by the Japanese
After the Leyte Gulf was secured, the Pacific Fleet moved its forward
staging area to Leyte, and
Ulithi was all but abandoned. In the end,
few US civilians ever heard of Ulithi. By the time Naval security
cleared release of the name, there were no longer reasons to print
stories about it. The war had moved on, but for seven months in late
1944 and early 1945, the large lagoon of the
Ulithi atoll was the
largest and most active anchorage in the world.
In an annual report released in early 2010, the
announced plans to develop and distribute native-language materials
for educators and students in the outer islands of
Micronesia. The first project was a Ulithian-to-English
dictionary. This was the first rigorous documentation of the
Ulithian language, and copies were provided to educators and students
Ulithi and Fais The authors' stated aim was to create a
consistent and intuitive Latin alphabet useful for both native
Ulithian and native English speakers.
Yap Outer Islands High School
^ "Ulithi". Yapese Dictionary: English Finderlist. Updated 27 July
2012. Retrieved 25 November 2013.
^ "Mississinewa (AO-59) I". Dictionary of American Naval Fighting
Ships. Navy Department, Naval History and Heritage Command.
^ a b Fulleman, Bob (November 2009). "AO-59 USS Mississinewa".
^ "Finlayson Files". Finlayson Files. Retrieved 2015-09-07.
^ Quanchi, Max (2005). Historical Dictionary of the Discovery and
Exploration of the Pacific Islands. The Scarecrow Press.
pp. 215–216. ISBN 0810853957.
^ Langdon, Robert (1975). The Lost Caravel. Sidney: Pacific
Publications. p. 268. ISBN 978-0-85807-021-9.
^ Sharp, Andrew The discovery of the Pacific Islands Oxford, 1960,
^ Brand, Donald D. (1967). The Pacific Basin: A History of its
Geographical Explorations. New York: The American Geographical
Society. p. 123.
^ Burney, James (1817). A Chronological History of the Discoveries of
the South Sea or Pacific Ocean: To the year 1764. London: Luke Hansard
& Sons. ISBN 978-1-108-02411-2.
^ Jones, Brent (December 2007). "Chapter 8: Reporting For Duty".
Mighty Ninety, The Homepage of USS Astoria CL-90.
^ "Building the Navy's Bases in World War II: History of the Bureau of
Yards and Docks and the Civil Engineering Corps, 1940-1946, Volume
II". Washington, DC: United States Government Printing Office. 1947.
p. 332. Retrieved 18 May 2015.
^ a b c d Spangler, George (March 1998). "Ulithi". USS Laffey.
^ Antill, Peter (28 February 2003). "Battle for Anguar and Ulithi
(Operation Stalemate II) September 1944". Military History
Encyclopedia on the Web.
^ a b "ServRon 10: Floating Arsenal". Popular Mechanics: 59. November
1945. Retrieved 18 May 2015.
^ Slagg, John. "Where is Mog Mog?".
^ "World Battlefronts: Mighty Atoll". Time. August 6, 1945.
^ "Building the Navy's Bases in World War II: History of the Bureau of
Yards and Docks and the Civil Engineering Corps, 1940-1946, Volume
II". Washington, D.C.: United States Government Printing Office. 1947.
p. 334. Retrieved 18 May 2015.
^ Morison, Samuel Eliot (1958). History of United States Naval
Operations in World War II: Leyte. Little, Brown and Company.
pp. 47–50. ISBN 0-252-07063-1.
^ "Japanese submarine losses". Retrieved 16 September 2010.
^ Arnold, Bruce Makoto (August 2007). An
Atoll on the Edge of Hell:
The U.S. Military's use of
Ulithi During World War II (M.A. Thesis).
Sam Houston State University. OCLC 173485609.
^ Potter, E. B. (2005). Admiral Arliegh Burke. U.S. Naval Institute
Press. ISBN 978-1-59114-692-6. p. 241
^ Bob Hackett (2007). "Operation Tan No. 2: The Japanese Attack on
Task Force 58's Anchorage at Ulithi".
^ "FORMER MICRONESIA PEACE CORPS GROUP FUNDS SCHOLARSHIPS" Pacific
Island Report, East-West Center, January 28, 2010.
^ "Charity Publishes Dictionary For Remote Micronesian Islanders "
COM-FSM, May 10, 2010.
^ "Higher Education in the Federated States of Micronesia." Embassy of
Federated States of Micronesia
Federated States of Micronesia Washington DC. Retrieved on
February 23, 2018.
Wikimedia Commons has media related to Ulithi.
Ulithi South Pacific Naval Base George Spangler, March 1998
Ulithi World War II Project
Account of the March 11, 1945 kamikaze attack on Randolph.
Habele, an educational charity serving Ulithi
Coordinates: 9°58′N 139°40′E / 9.97°N 139.67°E /