Two Japanese Ships Sunk Off the US Coast During WWII Discovered

During World War II, the seas around the world were grounds of intense naval warfare, and many ships met their tragic ends. For over 80 years, the only two Japanese ships believed to have been lost right off the coast of the United States remained undiscovered. This changed recently when a dedicated team of researchers found them near the coast of Alaska, an event that focuses attention on the lesser-known aspects of the war in the Pacific.

Underwater Archaeological Mission on Attu Island

In July 2024, researchers embarked on an underwater archaeological mission off Attu Island. This team, led by Dominic Bush from Ships of Discovery, Inc., aimed to uncover more about the island’s rich history. The goals included finding evidence of human occupation going back 3,000 years, exploring the remains from World War II, and learning about Attu’s marine ecology. What made this expedition remarkable was the discovery of the wrecks of the Kotohira Maru and Cheribon Maru, two Japanese ships with stories tied to the turbulent times of WWII.

The Kotohira Maru, a 5,000-ton freighter, played a significant role in supplying the Japanese forces stationed on Attu. On January 5, 1943, a US Navy weather plane attacked the ship while she was on her supply run, causing her to sink. The team found the remains of the Kotohira Maru about 300 feet underwater, just over half a mile from its last reported location. Despite the attack that broke off its bow, the ship was found relatively intact. The discovery served as a somber reminder of the lives lost aboard.

The Cheribon Maru, a 3,000-ton freighter, faced a different fate. On Thanksgiving Day in 1942, American bomber aircraft attacked the ship, leading to its sinking. Unlike the Kotohira Maru, the Cheribon Maru was found in a deteriorated state, covered in kelp and showing significant damage from the attack. These shipwrecks serve as time capsules, offering insights into the naval battles that occurred off the American coastline during WWII.

The Aleutian Islands Campaign and Underwater Discoveries

The Aleutian Islands Campaign is often overshadowed by other battles fought during World War II, even though it was the only campaign that witnessed combat on North American soil. In 1942, Japanese forces attacked Dutch Harbor and subsequently captured Attu Island. The capture led to sustained air raids by American forces until May 1943 when US troops mounted an amphibious assault to reclaim the island. This battle marked a crucial episode in the Aleutian Islands Campaign. The US victory allowed them to establish a military outpost on Attu, changing the course of the campaign.

The expedition that uncovered these wrecks involved experts from various fields, including archaeology, robotics, and hydrography, from both the United States and Japan. They used various advanced technological tools, such as synthetic aperture sonar, remotely operated vehicles (ROVs), and acoustic imaging technology to map the underwater landscape. Through their thorough investigation, the researchers identified three shipwrecks, among them the Kotohira Maru and Cheribon Maru.

A third ship, the SS Dellwood—a US Army cable layer—was also discovered during the expedition. The Dellwood met its end after hitting a submerged pinnacle, leading to its eventual sinking when it was being towed to a dock. Because it became a navigational hazard, it was later intentionally blown up.

Discoveries of WWII-Era Artifacts and Renewed Interest in the Aleutian Islands Campaign

The researchers also found a variety of World War II-era artifacts lying on the seafloor. These included dozens of anchors, chains, mooring blocks, sunken buoys, and materials used in constructing wartime bases. Anti-submarine netting was also discovered, offering a glimpse into the defensive measures taken during the war.

Overall, this project marks a renewed interest in the Aleutian Islands Campaign and Alaska’s role in WWII history. Jason Raupp of East Carolina University emphasized the importance of this discovery, noting that it will likely lead to more focus on this oft-forgotten chapter of the war. The expedition was made possible through grants from the National Oceanic Atmospheric Administration’s (NOAA) Ocean Exploration Program and the National Park Service’s (NPS) American Battlefield Protection Program.