Ulithi north anchorage and Sorlen Island

Map of the Federated States of Micronesia CIA

US Naval Base Carolines included a number of

United States Navy The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...

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 cen ...

in the western Pacific Ocean, to the north of

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...

during

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

. The bases were built to support the

island hopping Leapfrogging was an amphibious military strategy employed by the Allies in the Pacific War against the Empire of Japan during World War II. The key idea was to bypass heavily fortified enemy islands instead of trying to capture every island i ...

Pacific War The Pacific War, sometimes called the Asia–Pacific War or the Pacific Theatre, was the Theater (warfare), theatre of World War II fought between the Empire of Japan and the Allies of World War II, Allies in East Asia, East and Southeast As ...

efforts of the allied nations fighting the

Empire of Japan The Empire of Japan, also known as the Japanese Empire or Imperial Japan, was the Japanese nation state that existed from the Meiji Restoration on January 3, 1868, until the Constitution of Japan took effect on May 3, 1947. From Japan–Kor ...

History

The Caroline Islands is now the

Federated States of Micronesia The Federated States of Micronesia (, abbreviated FSM), or simply Micronesia, is an island country in Micronesia, a region of Oceania. The federation encompasses the majority of the Caroline Islands (excluding Palau) and consists of four Admin ...

nation. Micronesia comprises

Kosrae State Kosrae ( ), formerly known as Kusaie or Strong's Island, is an island in the Caroline Islands archipelago, and state within the Federated States of Micronesia. It includes the main island of Kosrae, traditionally known as Ualung (which means the ...

, Pohnpei State,

Chuuk State Chuuk State (; also known as Truk) is one of the four states of the Federated States of Micronesia (FSM). It consists of several island groups: Nomoneas, Faichuk, Faichuuk, the Hall Islands, Namonuito Atoll (Magur Islands), Pattiw (Western Isl ...

(in past spelled Truk) and

Yap State Yap State ( or ) is one of the four states of the Federated States of Micronesia, located in the westernmost portion of the country. The state borders Palau to the southwest, Guam to the north, and Chuuk State to the east. According to the state' ...

. After the

Spanish–American War The Spanish–American War (April 21 – August 13, 1898) was fought between Restoration (Spain), Spain and the United States in 1898. It began with the sinking of the USS Maine (1889), USS ''Maine'' in Havana Harbor in Cuba, and resulted in the ...

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

World War I World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...

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 was a peace treaty signed on 28 June 1919. As the most important treaty of World War I, it ended the state of war between Germany and most of the Allies of World War I, Allied Powers. It was signed in the Palace ...

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 Ocean. It lies about 1,800 kilometres (970 nautical miles) northeast of New Guinea and is part of Chuuk State within the Federated States of Micronesia (FSM). A protective ...

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 (formerly known as Ponape or Ascension, from Pohnpeian: "upon (''pohn'') a stone altar (''pei'')") is an island of the Senyavin Islands which are part of the larger Caroline Islands group. It belongs to Pohnpei State, one of the fou ...

. 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 Pohnpei State in 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 ...

and it 8,000 troops. The

United States Armed Forces The United States Armed Forces are the Military, military forces of the United States. U.S. United States Code, federal law names six armed forces: the United States Army, Army, United States Marine Corps, Marine Corps, United States Navy, Na ...

built a large base at

Ulithi Atoll Ulithi (, , or ; pronounced roughly as YOU-li-thee) is an atoll in the Caroline Islands of the western Pacific Ocean, about east of Yap, within Yap State. Name The name of the island goes back to Proto-Chuukic ''*úlú-diwo''. Overview U ...

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 Forces (NCF). The Seabee nickname is a heterograph of the initial letters "CB" from the words "Construction Battalion". Dependi ...

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 pu ...

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. The Imperial Japanese South Seas Mandate had been seized by the U.S. during the Pacifi ...

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 a 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-hopping Pacific Wa ...

, FPO# 3011 * Naval Base Peleliu on

Palau Palau, officially the Republic of Palau, is an island country in the Micronesia subregion of Oceania in the western Pacific Ocean. The Republic of Palau consists of approximately 340 islands and is the western part of the Caroline Islands ...

Islands. **Naval base

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

, 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 declar ...

* Naval Base at

Uman Island Uman Island is an island of Uman municipality in Chuuk State, Federated States of Micronesia, with an area of 4.70 km². Highest elevation is Mt. Uroras with 273 meters. Traditionally and before European contact, Uman had been subdivided into s ...

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

Naval Base Kossol Roads file:Palau on the globe (Southeast Asia centered) (small islands magnified).svg, 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 a ...

, 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 t ...

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 (, sometimes written as , or ) 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 ...

, 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 Minto Reef is a largely submerged atoll belonging to Pohnpei State in Micronesia. Description Minto Reef encloses a lagoon of about 25 to 30 km2 in area. There are several boat passages into the lagoon on the southern side. It is at the sam ...

, FPO#3038 * Naval Base at

Pulap Pulap or Pollap is an atoll in Chuuk State, Federated States of Micronesia, 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 weste ...

Island, FPO#3039 * Naval Base at

Pakin ''Pakin'' (or gallicised ''Pakine'', ) is an Armenian-language literary and cultural periodical published in Beirut, Lebanon since 1962. The magazine was founded by Garo Sassouni as executive editor and Yetvart Boyajian and Boghos Snabian as edit ...

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 ...

, 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 centr ...

, 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 22 islands in the western Caroline Islands in the Pacific Ocean, forming a legislative district in the Yap State in the Federated States of Micronesia, and located approximately west-northwest ...

Island, FPO#3246, post war surrendered

Woleai airfield Woleai (), also known as Oleai, is a coral atoll of 22 islands in the western Caroline Islands in the Pacific Ocean, forming a legislative district in the Yap State in the Federated States of Micronesia, and located approximately west-northwest ...

. * 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, ...

, 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 hopping 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 ...

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

Operation Hailstone Operation Hailstone was a large-scale United States Navy air and surface attack on Truk Lagoon on 17–18 February 1944, conducted as part of the American offensive drive against the Imperial Japanese Navy in the Pacific Ocean theatre of Worl ...

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

. *Eten Airfield on

Eten Island Etten is an island in Chuuk Lagoon (previously known as Truk Lagoon), in the Federated States of Micronesia. It is located 620 meters to the south of Dublon Island and has an area of 52 hectares. It is part of Tonoas (Dublon) municipality, and for ...

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 betwe ...

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 List of auxiliaries of the United States Navy, auxiliary Dry dock#Floating, floating dry dock. Floating dry docks are able to submerge underwater and to be placed under a ship in need of repai ...

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 Hailstoneyoutube.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