Ulithi north anchorage and Sorlen Island

Map of the Federated States of Micronesia CIA

US Naval Base Carolines was number of

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

bases on the

Caroline Islands The Caroline Islands (or the Carolines) are a widely scattered archipelago of tiny islands in the western Pacific Ocean, to the north of New Guinea. Politically, they are divided between the Federated States of Micronesia (FSM) in the centra ...

in the western Pacific Ocean, to the north of

New Guinea New Guinea (; Hiri Motu Hiri Motu, also known as Police Motu, Pidgin Motu, or just Hiri, is a language of Papua New Guinea, which is spoken in surrounding areas of Port Moresby (Capital of Papua New Guinea). It is a simplified version of ...

during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

. The bases were built to support the island hoping

Pacific war The Pacific War, sometimes called the Asia–Pacific War, was the theater of World War II that was fought in Asia, the Pacific Ocean, the Indian Ocean, and Oceania. It was geographically the largest theater of the war, including the vast ...

efforts of the

allied nations The Allies, formally referred to as the United Nations from 1942, were an international military coalition formed during the Second World War (1939–1945) to oppose the Axis powers, led by Nazi Germany, Imperial Japan, and Fascist Italy ...

fighting the

Empire of Japan The also known as the Japanese Empire or Imperial Japan, was a historical nation-state and great power that existed from the Meiji Restoration in 1868 until the enactment of the post-World War II 1947 constitution and subsequent fo ...

History

The Caroline Islands is now the

Federated States of Micronesia The Federated States of Micronesia (; abbreviated FSM) is an island country in Oceania. It consists of four states from west to east, Yap, Chuuk, Pohnpei and Kosraethat are spread across the western Pacific. Together, the states comprise a ...

nation. Micronesia comprises

Kosrae State Kosrae ( ), formerly known as Kusaie or Strong's Island, is an island in the Federated States of Micronesia. The State of Kosrae is one of the four states of the Federated States of Micronesia, and includes the main island of Kosrae and a few near ...

Pohnpei State Pohnpei State (IPA: pɔ:n peɪ) is one of the four states of the Federated States of Micronesia (FSM). The other states are, from east to west, Kosrae State, Chuuk State, and Yap State. The state's main island is Pohnpei. History The pre-colonia ...

Chuuk State Chuuk State (; also known as Truk) is one of the four states of the Federated States of Micronesia (FSM). The other states are Kosrae State, Pohnpei State, and Yap State. It consists of several island groups: * Namoneas * Faichuuk * Hall Isla ...

(in past spelled Truk) and

Yap State Yap State, also known in the Yapese language as Nam nu Wa'ab (lit. "Island of Yap") or simply as Wa'ab, is one of the four states of the Federated States of Micronesia (FSM). The other states are Kosrae State, Pohnpei State, and Chuuk State. C ...

. After the

Spanish–American War , partof = the Philippine Revolution, the decolonization of the Americas, and the Cuban War of Independence , image = Collage infobox for Spanish-American War.jpg , image_size = 300px , caption = (clock ...

in 1898, the islands became a German colony and German naval base. At the start of

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

in 1914 British warships destroyed the German colonial plantation owner's radio station. On October 7, 1914, Japan invaded and took over Yap island without a battle. Japan and Britain made a treaty giving Japan the Pacific islands north of the Equator, signed at the

Treaty of Versailles The Treaty of Versailles (french: Traité de Versailles; german: Versailler Vertrag, ) was the most important of the peace treaties of World War I. It ended the state of war between Germany and the Allied Powers. It was signed on 28 June ...

in 1919. In the 1930s Japan built naval and airbases on many of the islands.

Truk Lagoon Chuuk Lagoon, previously Truk Atoll, is an atoll in the central Pacific. It lies about northeast of New Guinea, and is part of Chuuk State within the Federated States of Micronesia (FSM). A protective reef, around, encloses a natural harbou ...

was the largest and strongest of these bases. The

United States Army Air Forces The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II ...

bombed the Truk base, but it was bypassed in the

amphibious landing Amphibious warfare is a type of offensive military operation that today uses naval ships to project ground and air power onto a hostile or potentially hostile shore at a designated landing beach. Through history the operations were conducted ...

war. Japan's Truk base had five airfields, fleet anchorage, a few seaplane bases, torpedo boat bases, repair facilities, and later a radar station. Japan also built a large base at Ponape, now

Pohnpei Pohnpei "upon (''pohn'') a stone altar (''pei'')" (formerly known as Ponape or Ascension, Proto-Chuukic-Pohnpeic: ''*Fawo ni pei)'' is an island of the Senyavin Islands which are part of the larger Caroline Islands group. It belongs to Pohnpei ...

. By February 1944, the US bombers destroyed Truk and by sea, the US Navy cut had cut off Truk and the 5,000 Japanese troops. The US also bypassed Ponape in the

Senyavin Islands The Senyavin Islands belong to the Federated States of Micronesia. They consist of a larger volcanic Pohnpei Island (about 334 km2) and two small atolls Ant and Pakin. History On Pohnpei, pre-colonial history is divided into three eras: ...

and it 8,000 troops. The

United States Armed Forces The United States Armed Forces are the military forces of the United States. The armed forces consists of six service branches: the Army, Marine Corps, Navy, Air Force, Space Force, and Coast Guard. The president of the United States is the ...

built a large base at

Ulithi Atoll Ulithi ( yap, Wulthiy, , or ) is an atoll in the Caroline Islands of the western Pacific Ocean, about east of Yap. Overview Ulithi consists of 40 islets totaling , surrounding a lagoon about long and up to wide—at one of the largest ...

in the Yap islands, as it had a large fleet anchorage for up to 700 ships. The US Army 81st Division landed unopposed on Ulithi on September 23, 1944. Soon US Navy

Seabees United States Naval Construction Battalions, better known as the Navy Seabees, form the U.S. Naval Construction Force (NCF). The Seabee nickname is a heterograph of the initial letters "CB" from the words "Construction Battalion". Depending upon ...

started work building the large base at Ulithi. The US Navy

survey ship A survey vessel is any type of ship or boat that is used for underwater surveys, usually to collect data for mapping or planning underwater construction or mineral extraction. It is a type of research vessel, and may be designed for the purpo ...

found the lagoon was well protected and usable for fleet anchorage. Japan bombed the US base at Ulithi a few times, with only marginal damage. The Fleet Post Office (FPO) for Caroline Islands was # 3249. After the war, the Caroline Islands became parts of the

Trust Territory of the Pacific Islands The Trust Territory of the Pacific Islands (TTPI) was a United Nations trust territory in Micronesia administered by the United States from 1947 to 1994. History Spain initially claimed the islands that later composed the territory of the Trus ...

administered by the United States. In 1986, the new nation of the Federated States of Micronesia was formed. Independence was proclaimed on May 10, 1979, and Compact of Free Association was established on November 3, 1986.

Major bases

Naval Base Ulithi Naval Base Ulithi was major United States Navy base at the Ulithi Atoll in the Caroline Islands in the western Pacific Ocean, to the north of New Guinea during World War II. The base was built to support the island hoping Pacific war e ...

, FPO# 3011 *

Naval Base Peleliu Peleliu Naval Base was a major United States Navy sea and airbase base on Peleliu island, one of sixteen states of Palau. The United States Marine Corps took the island in the Battle of Peleliu during World War II. Battle of Peleliu was a cost ...

Palau Palau,, officially the Republic of Palau and historically ''Belau'', ''Palaos'' or ''Pelew'', is an island country and microstate in the western Pacific. The nation has approximately 340 islands and connects the western chain of the Caro ...

Islands. **Naval base

Angaur Island , or in Palauan, is an island and state in the Island country, island nation of Palau. History Angaur was traditionally divided among some eight clans. Traditional features within clan areas represent important symbols giving identity to fam ...

, on Palau Islands, base to support

Angaur Airstrip Angaur Airstrip (Japanese: アンガウル飛行場, Hepburn: Angauru hikōjō, ) is a small airstrip on Angaur, one of the islands of Palau. It also served as an airfield during World War II. History World War II The day the island was declare ...

* Naval Base at

Uman Island Uman Island is an island of Uman municipality in Chuuk State, Federated States of Micronesia. During World War II the United States Navy built Naval Base at Uman Island, Truk Lagoon, Fleet Post Office #3048. The United States Fourth Fleet ...

, Truk Lagoon, FPO#3048, 4th Fleet anchorage, PT Boat Base. *

Naval Base Kossol Roads Palau on the globe, Kossol Roads is at the north end of islands in redNaval Base 1944–1945 Naval Base Kossol Roads also called Naval Base Kossol Passage was major United States Navy base at Kossol Roads in northern Palau in the western Ca ...

, FPO#3027, Fleet anchorage a surrendered base, staging area to support operations in the Philippines.

Service Squadron A Service Squadron (ServRon) was a United States Navy squadron that supported fleet combat ships and US Navy Auxiliary ships. Service Squadrons were used by the US Navy from their inception in 1943 to as late as the early 1980s. At the time of th ...

was stationed at Kossol Roads as a floating resupply and repair base.

Minor bases

* Naval Base at Puluwat Island, Truk Lagoon, FPO#3044 * Naval Base at Fefan Island, Truk Lagoon, FPO#3045, captured seaport * Naval Base at

Yap Island Yap ( yap, Waqaab) traditionally refers to an island group located in the Caroline Islands of the western Pacific Ocean, a part of Yap State. The name "Yap" in recent years has come to also refer to the state within the Federated States of Micro ...

, FPO#3014, captured base * Naval Base at Param Island, Truk Lagoon, FPO#3050, post war surrendered Airfield * Naval Base at Tol Island, Truk, FPO#3105, post war surrendered base * Naval Base at Sorol Island, FPO#3012, post war surrendered small base * Naval Base at

Namonuito Atoll Namonuito Atoll, also called Namonweito, Weito, or Magur Islands, is the largest atoll of the Federated States of Micronesia and of the Caroline Islands with a total area of , unless one considers the still larger Chuuk (Truk) Lagoon as a type o ...

, FPO#3037 * Naval Base at Minto Reef, FPO#3038 * Naval Base at

Pulap Pulap or Pollap is an atoll with a total area (including the lagoon) of , of which is emergent land, consisting of three islands, Pollap in the north, Tamatam in the south, and Fanadik at the western fringe of the reef. The atoll is located in th ...

Island, FPO#3039 * Naval Base at

Pakin ''Pakin'' (or francicized ''Pakine'') (in Armenian Բագին meaning altar in Armenian, full name at establishment Բագին, Ամսագիր Գրականութեան եւ Արուեստի, i.e. ''Pakin, Amsakir Kraganutyan yev Arvesdi'', meaning ...

Island,

FPO#3064 * Naval Base at Ant Island, in Senyavin Islands, FPO#3067 * Naval Base at

Oroluk Atoll Oroluk Atoll is an atoll belonging to Pohnpei State in the Micronesia. Description Oroluk Atoll stretches from the northwest to the southeast with a length of about and an average width of . The lagoon's surface is roughly . The more than 25 sa ...

, FPO#3075, Oroluk Island had a lookout tower and Oroluk Lagoon for anchorage. * Naval Base at

Ngulu Atoll Ngulu Atoll is a coral atoll of three islands in the Caroline Islands in the Pacific Ocean, and forms a legislative district in Yap State in the Federated States of Micronesia. Ngulu extends for by with 18 reef segments enclosing a deep central ...

, FPO#3079 * Naval Base at Namolus Island, FPO#3081 * Naval Base at Tonelik Island, FPO#3082, post war surrendered small base * Naval Base at

Woleai Woleai, also known as Oleai, is a coral atoll of twenty-two islands in the western Caroline Islands in the Pacific Ocean, and forms a legislative district in the Yap State in the Federated States of Micronesia and is located approximately west-n ...

Island, FPO#3246, post war surrendered

Woleai airfield Woleai, also known as Oleai, is a coral atoll of twenty-two islands in the western Caroline Islands in the Pacific Ocean, and forms a legislative district in the Yap State in the Federated States of Micronesia and is located approximately west- ...

. * Naval Base at

Hall Islands The Hall Islands are a group of two large atolls in the northern part of the state of Chuuk, Federated States of Micronesia. In the broader sense, a third and smaller atoll is included. Nomwin, the western atoll, and Murilo, the eastern one, a ...

, FPO#3061, located to the north of Truk Lagoon. *Small Naval base to support

Fais Airfield Fais Island is a raised coral island in the eastern Caroline Islands in the Pacific Ocean, and forms a legislative district in Yap State in the Federated States of Micronesia. Fais Island is located approximately east of Ulithi and northeast o ...

* Colonia Airfield post war surrendered a small base

American missions against Japan Carolines

From the US Naval Base Carolines the US had many missions against Japan bases in the Carolines. Japan's base at Truk, that the US Navy called ''The "Gibraltar of the Pacific'', was invasion bypassed in the island hoping Pacific war efforts. Truk had over 30,000 troops, seaport, five airstrips, a seaplane bases, a torpedo boat station, a submarine base and

coastal artillery Coastal artillery is the branch of the armed forces concerned with operating anti-ship artillery or fixed gun batteries in coastal fortifications. From the Middle Ages until World War II, coastal artillery and naval artillery in the form of c ...

. Truk was attacked by air and had its supply lines cut off by sea, called

Operation Hailstone Operation Hailstone ( ja, トラック島空襲, Torakku-tō Kūshū, lit=airstrike on Truk Island), 17–18 February 1944, was a massive United States Navy air and surface attack on Truk Lagoon conducted as part of the American offensive drive ...

. *Truk Atoll: *Param Airfield on Param Island in

. *Eten Airfield on Eten Island in Truk Lagoon. *Megeson Airfield (Megeson) started in 1944 not completed. *Dublon Seaplane Base on Dublon Island and Truk Lagoon *Reef Islands base at Truk *Polle Island base at Truk * Eot Island base *Pata Island base * Fala-Beguets Island base *Yawata Island base (Yawata Shima) *Salat Island base *Northeast Island *Falo Island base * Udot Island base * Moen Island (Weno) in Truk Lagoon, two airfields and seaplane base: ** Moen No. 1 Airfield now

Chuuk International Airport Chuuk International Airport is an airport located on Weno (formerly Moen), the main island of the State of Chuuk (formerly Truk) in the Federated States of Micronesia. History Chuuk International Airport was originally built by Japan between ...

the northwestern tip of Moen Island. **Moen No. 2 Airfield now part of Chuuk International Airport, located at the southwestern corner of Moen Island. **Moen Seaplane Base was at the southwestern corner of Moen Island.

Post war

* Pohnpei Airport built by a US Navy civil engineering team in 1972.Pohnpei Airport
'pacificwrecks.com''

Gallery

File:Pacific_Theater_Areas;map1.JPG, Pacific War Theater Areas map 1942 Japanese shipping under attack in Truk Lagoon during Operation Hailstone, 17 February 1944 (80-G-215151).jpg, Japanese ships burning off Dublon Island, Truk Lagoon, on the first day of air strikes conducted as part of

File:Japanese ammunition ship Aikoku Maru in Truk Harbor explodes.jpg, Japanese ammunition ship ''Aikoku Maru'' in Truk Harbor explodes File:Falalop Island- Ulithi Atoll.JPG, Falalop Island in Ulithi Atoll File:Second world war asia 1943-1945 map de.png, Second world war leapfrogging strategy 1943-1945 map File:Ulithi-atoll.gif, Ulithi atoll File:USS Shannon (DM-25) underway in Ulithi Atoll, circa in March 1945 (80-G-K-3816).jpg, USS ''Shannon'' (DM-25) in Ulithi Atoll in March 1945 File:Ulithi.jpg, Map of Ulithi Atoll File:USS Iowa Floating Drydock.jpg, USS ''Iowa'' in a

Auxiliary floating drydock An auxiliary floating drydock is a type of US Navy floating dry dock. Floating dry docks are able to submerge underwater and to be placed under a ship in need of repair below the water line. Water is then pumped out of the floating dry dock, r ...

at Ulithi File:Iwo jima location mapSagredo.png, Map Japan and the Carolines File:South Pacific islands 1945.jpg, South Pacific islands in 1945

External links

youtube.com_Operation_Hailstone
.html" ;"title="Operation Hailstone">youtube.com Operation Hailstone
">Operation Hailstone">youtube.com Operation Hailstone
br>youtube.com Ulithi Atoll Anchorage Aerial Views of US Navy 5th Fleet at Anchor

youtube.com 1940s World War II: Ulithi, Anchorageyoutube.com US air operations at newly built airstrip on Ulithi Atoll in World War II HD Stock Footage

References

{{Federated States of Micronesia topics Naval Stations of the United States Navy World War II airfields in the Pacific Ocean Theater Airfields of the United States Navy Military installations closed in the 1940s Closed installations of the United States Navy