was the second vessel in the of medium-sized minelayer

Minelayer

Minelaying is the act of deploying explosive mines. Historically this has been carried out by ships, submarines and aircraft. Additionally, since World War I the term minelayer refers specifically to a naval ship used for deploying naval mines...

s of the Imperial Japanese Navy

Imperial Japanese Navy

The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...

, which was in service during World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. She was designed as an improved version of Shirataka

Japanese minelayer Shirataka

was a medium-sized minelayer of the Imperial Japanese Navy, which was in service during the Second Sino-Japanese War and World War II. She was the world's first purpose-built anti-submarine netlayer...

 netlayer. However, during the Pacific War

Pacific War

The Pacific War, also sometimes called the Asia-Pacific War refers broadly to the parts of World War II that took place in the Pacific Ocean, its islands, and in East Asia, then called the Far East...

, due to the critical shortage of patrol ships for convoy escort duties, she was fitted with depth charge

Depth charge

A depth charge is an anti-submarine warfare weapon intended to destroy or cripple a target submarine by the shock of exploding near it. Most use explosives and a fuze set to go off at a preselected depth in the ocean. Depth charges can be dropped by either surface ships, patrol aircraft, or from...

 racks and her minelaying rails were removed.

Building

Under the Maru-3

3rd Naval Armaments Supplement Programme (Japan, 1937)

The otherwise known as the "Circle Three" Plan was the third of four expansion plans of the Imperial Japanese Navy between 1930 and the start of World War II.-Background:...

 Supplemental Armaments Budget of 1937, the Imperial Japanese Navy authorized a two vessels of a new class of minelayer (Project number H12) primarily for coastal duties. The new vessel was designed to carry either 100 Type 5 naval mine

Naval mine

A naval mine is a self-contained explosive device placed in water to destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, an enemy vessel...

s, or to function as a netlayer

Net laying ship

A net laying ship, also known as a net layer, net tender or boom defence vessel was a type of small auxiliary ship.A net layer's primary function was to lay and maintain steel anti-torpedo or anti-submarine nets. Nets could be laid around an individual ship at anchor, or around harbors or other...

 based on design features developed through operational experience with Shirataka.

Aotaka was launched by the Harima Shipyard near Kobe

Kobe

, pronounced , is the fifth-largest city in Japan and is the capital city of Hyōgo Prefecture on the southern side of the main island of Honshū, approximately west of Osaka...

 on February 3, 1940, and was commissioned into service on June 30, 1940.

Operational history

After commissioning, Aotaka was assigned to the Maizuru Naval District

Maizuru Naval District

was one of four main administrative districts of the pre-war Imperial Japanese Navy. Its territory included the entire Sea of Japan coastline from northern Kyūshū to western Hokkaidō.-History:...

, but was soon reassigned to become flagship

Flagship

A flagship is a vessel used by the commanding officer of a group of naval ships, reflecting the custom of its commander, characteristically a flag officer, flying a distinguishing flag...

 of the First Second Base Force of the IJN 2nd Fleet

IJN 2nd Fleet

The was a fleet of the Imperial Japanese Navy.-History:First established on 28 December 1903, the IJN 2nd Fleet was created by the Imperial General Headquarters as a mobile strike force of cruisers and destroyers to pursue the Imperial Russian Navy's Vladivostok-based cruiser squadron while the...

. On March 23, 1941, she was assigned to patrols of the central China

China

Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

 coastline. On April 10, 1941, Aotaka was reassigned to the IJN 3rd Fleet

IJN 3rd Fleet

The was a fleet of the Imperial Japanese Navy, which was created on six separate occasions.-Russo-Japanese War:First established on 28 December 1903, the IJN 3rd Fleet was created by the Imperial General Headquarters as an administrative unit to manage various vessels considered too obsolete for...

, and continued its deployment on the China coast through the end of November.

At the time of the attack on Pearl Harbor

Attack on Pearl Harbor

The attack on Pearl Harbor was a surprise military strike conducted by the Imperial Japanese Navy against the United States naval base at Pearl Harbor, Hawaii, on the morning of December 7, 1941...

 in December 1941, Aotaka was assigned to "Operation M", (the invasion of the northern Philippines) , escorting several convoys of transports between the Japanese home islands, Palau

Palau

Palau , officially the Republic of Palau , is an island nation in the Pacific Ocean, east of the Philippines and south of Tokyo. In 1978, after three decades as being part of the United Nations trusteeship, Palau chose independence instead of becoming part of the Federated States of Micronesia, a...

 and landing zones in the Philippines

Philippines

The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...

.

In January 1942, Aotaka was assigned to ”Operation H” (the invasion of the Celebes

Sulawesi

Sulawesi is one of the four larger Sunda Islands of Indonesia and is situated between Borneo and the Maluku Islands. In Indonesia, only Sumatra, Borneo, and Papua are larger in territory, and only Java and Sumatra have larger Indonesian populations.- Etymology :The Portuguese were the first to...

 in the Netherlands East Indies, supporting landings at Kendari

Kendari

Kendari is the capital of the Indonesian province of South East Sulawesi. The city lies along Kendari Bay. Moramo Waterfall is located 65 km east of Kendari. Kendari is divided into four subdistricts: Kendari, Mandonga, Baruga, and Poasia...

 and Makassar

Makassar

Makassar, is the provincial capital of South Sulawesi, Indonesia, and the largest city on Sulawesi Island. From 1971 to 1999, the city was named Ujung Pandang, after a precolonial fort in the city, and the two names are often used interchangeably...

, and later supporting ”Operation J”

Battle of Java (1942)

The Battle of Java was a battle of the Pacific theatre of World War II. It occurred on the island of Java from 28 February-12 March 1942. It involved forces from the Empire of Japan, which invaded on 28 February 1942, and Allied personnel...

, the invasion Java

Java

Java is an island of Indonesia. With a population of 135 million , it is the world's most populous island, and one of the most densely populated regions in the world. It is home to 60% of Indonesia's population. The Indonesian capital city, Jakarta, is in west Java...

 and Bali

Bali

Bali is an Indonesian island located in the westernmost end of the Lesser Sunda Islands, lying between Java to the west and Lombok to the east...

. On March 10, Aotaka was re-assigned to the Second Southern Expeditionary Fleet, spending much of the rest of the year escorting convoys between Surabaya

Surabaya

Surabaya is Indonesia's second-largest city with a population of over 2.7 million , and the capital of the province of East Java...

, and Singapore

Singapore

Singapore , officially the Republic of Singapore, is a Southeast Asian city-state off the southern tip of the Malay Peninsula, north of the equator. An island country made up of 63 islands, it is separated from Malaysia by the Straits of Johor to its north and from Indonesia's Riau Islands by the...

, from its base at Makassar.

In January 1943, Aotaka escorted the damaged from Ambon

Ambon Island

Ambon Island is part of the Maluku Islands of Indonesia. The island has an area of , and is mountainous, well watered, and fertile. Ambon Island consists of 2 territories: The main city and seaport is Ambon , which is also the capital of Maluku province and Maluku Tengah Ambon Island is part of the...

 to Makassar for repairs, and unsuccessfully attacked with depth charges on January 23. Aotaka continued with escort and patrol operations between Makassar, Singapore and Surabaya until reassigned to the Southwest Area Fleet

Southwest Area Fleet

The was a fleet of the Imperial Japanese Navy established during World War II.-History:The Southwest Area Fleet was an operational command of the Imperial Japanese Navy established on April 10, 1942 to coordinate naval, air, and ground forces for the invasion, occupation and defense of the...

 on July 30, when her zone of operations was shifted to Halmahera Island, the Moluccas and Makassar to mid-1944. On May 16, she suffered minor damage after striking a magnetic mine at Halmahera.

On June 3, Aotaka departed Singapore with a convoy bound for Moji, Kitakyūshū

Moji-ku, Kitakyushu

is a ward of Kitakyūshū, Fukuoka Prefecture, Japan. It is the former city of Moji which was one of five cities merged to create Kitakyūshū in 1963. It faces the city of Shimonoseki across the Kanmon Straits between Honshū and Kyūshū....

. The convoy was attacked by on June 6, but Aotaka was undamaged, and reached Maizuru Naval Arsenal

Maizuru Naval Arsenal

was one of four principal naval shipyards owned and operated by the Imperial Japanese Navy. -History:The Maizuru Naval District was established at Maizuru, Kyoto in 1889, as the fourth of the naval districts responsible for the defense of the Japanese home islands. After the establishment of the...

 for repairs on July 23. On September 1, Aotaka escorted a convoy from Mako

Mako Guard District

The was the major navy base for the Imperial Japanese Navy in Taiwan before and during World War II. Located in at Mako ), , the Mako Guard District was responsible for control of the strategic Straits of Taiwan and for patrols along the Taiwan and China coastlines and in the South China Sea...

 to Manila

Manila

Manila is the capital of the Philippines. It is one of the sixteen cities forming Metro Manila.Manila is located on the eastern shores of Manila Bay and is bordered by Navotas and Caloocan to the north, Quezon City to the northeast, San Juan and Mandaluyong to the east, Makati on the southeast,...

. After arriving safely, on September 21, approximately 200 aircraft from United States Navy

United States Navy

The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 Task Force 38 raided Manila Bay

Manila Bay

Manila Bay is a natural harbor which serves the Port of Manila , in the Philippines.The bay is considered to be one of the best natural harbors in Southeast Asia and one of the finest in the world...

; however, Aotaka avoided any damage. Aotaka then escorted a large convoy from Manila Bay to the presumed safety of Coron Bay

Coron Island

Coron Island is the third largest island in the Calamian Group of Islands in northern Palawan in the Philippines. The island is part of the larger municipality of the same name. It is about southwest of Manila, is known for several Japanese shipwrecks World War II vintage. The island is part of...

 at Busuanga Island

Busuanga Island

Busuanga Island is the largest island in the Calamian Group in the province of Palawan in the Philippines. Busuanga Island is, in fact, the second largest island in the province after Palawan island itself. The island is located halfway between the islands of Mindoro and Palawan with the South...

, Palawan

Palawan

Palawan is an island province of the Philippines located in the MIMAROPA region or Region 4. Its capital is Puerto Princesa City, and it is the largest province in the country in terms of total area of jurisdiction. The islands of Palawan stretch from Mindoro in the northeast to Borneo in the...

 on September 23. The following morning, the anchorage was attacked by 96 F6F Hellcat

F6F Hellcat

The Grumman F6F Hellcat was a carrier-based fighter aircraft developed to replace the earlier F4F Wildcat in United States Navy service. Although the F6F resembled the Wildcat, it was a completely new design powered by a 2,000 hp Pratt & Whitney R-2800. Some tagged it as the "Wildcat's big...

 and 24 SB2C Helldiver

SB2C Helldiver

The Curtiss SB2C Helldiver was a carrier-based dive bomber aircraft produced for the United States Navy during World War II. It replaced the Douglas SBD Dauntless in US Navy service. Despite its size, the SB2C was much faster than the SBD it replaced...

 aircraft from , and . Aotaka escaped from the ambush, but was spotted on September 26 by the submarine approximately 90 kilometers west of North Borneo

North Borneo

North Borneo was a British protectorate under the sovereign North Borneo Chartered Company from 1882 to 1946. After the war it became a crown colony of Great Britain from 1946 to 1963, known in this time as British North Borneo. It is located on the northeastern end of the island of Borneo. It is...

. Aotaka sank at 07°00′N 116°00′E.

Aotaka was removed from the navy list

Navy List

A Navy List or Naval Register is an official list of naval officers, their ranks and seniority, the ships which they command or to which they are appointed, etc., that is published by the government or naval authorities of a country....

on 10 November 1944.