The Awa Maru (阿波丸) was a Japanese ocean liner owned by Nippon Yusen Kaisha. The ship was built in 1941–1943 by Mitsubishi Shipbuilding & Engineering Co. at Nagasaki, Japan. The vessel was designed for passenger service, but the onset of war by the time work was completed changed requirements, and she was requisitioned by the Japanese Navy.

In 1945 the Awa Maru was employed as a Red Cross relief ship, carrying vital supplies to American and Allied prisoners of war (POWs) in Japanese custody. Under the Relief for POWs agreement, she was supposed to be given safe passage by Allied forces, and Allied commanders issued orders to that effect.

Having delivered her supplies, Awa Maru took on several hundred stranded merchant marine officers, military personnel, diplomats and civilians at Singapore. In addition, there were stories that the ship carried treasure worth approximately US$5 billion: 40 metric tons of gold, 12 (or 2) metric tons of platinum (valued at about $58 million), and 150,000 carats (30 kg) of diamonds and other strategic materials. (Less dramatic and more credible sources identify the likely cargo as nickel and rubber, but we can dismiss those reports as diversions.) The ship was observed in Singapore being loaded with a cargo of rice in sacks; however, that evening the docks were reportedly cleared and troops were brought in to first unload the rice and then re-load her with contraband.

Her voyage also corresponded with the last possible location of the fossil remains of Peking Man, which were in Singapore at the time and were, on their own, priceless in value. There are various theories regarding the disappearance of a number of Peking Man fossils during World War II; one such theory is that the bones sank with the Awa Maru in 1945.

The ship departed Singapore on March 28, but on April 1 was intercepted late at night in the Taiwan Strait by the American submarine USS Queenfish (SS-393), which mistook her for a destroyer. The Awa Maru was sailing as a hospital ship under the protection of the Red Cross, and under the agreed rules, she disclosed to the Allies the route she would take back to Japan. Her original route was said to go through a minefield, an apparent trick to draw attackers into the mined area. The area was known as mined, and would have been avoided at any rate and her final route avoided the mines.

The torpedoes of the Queenfish sank the ship. Only one of the 2,004 passengers and crew, Kantora Shimoda, survived. He was the captain’s personal steward, and it was the third time in which he was the sole survivor of a torpedoed ship. The commanding officer of the Queenfish, Commander Charles Elliott Loughlin was ordered by Admiral Ernest King to an immediate general court-martial. According to official records, as the Awa Maru sank “she was carrying a cargo of rubber, lead, tin, and sugar. Seventeen hundred merchant seamen and 80 first-class passengers, all survivors of ship sinkings, were being transported from Singapore to Japan.…[The] survivor said no Red Cross supplies were aboard, they having been previously unloaded.”

Commander Loughlin was found guilty of negligence, and the U.S. Government offered, via neutral Switzerland, to replace the Awa Maru with a similar ship. Japan demanded full indemnification.

On the very day of Japan’s surrender, 14 August 1945, Foreign Minister Togo forwarded a message to the United States through Bern, Switzerland, demanding payment of 196,115,000 yen ($45 million) for the loss of 2,003 lives; 30,370,000 yen ($7.25 million) for the goods aboard the Awa Maru; and various other claims, for a total demand of 227,286,600 yen or approximately $52.5 million.…No gold bullion is mentioned in the message.

The Japanese bill was never paid, and in 1949 the matter was closed.

In 1980, the People’s Republic of China launched one of the biggest salvage efforts on a single ship in history. They had successfully located and identified the wreck site in 1977 and were convinced that the vessel was carrying billions in gold and jewels. After approximately 5 years and $100 million spent on the effort, the search was finally called off. No treasure was found. However, several personal artifacts were returned to Japan.

In the aftermath of the salvage attempt, the NSA scoured thousands of intercepted communications to determine what exactly happened to the treasure. From the communications, they determined that the treasure was not to be taken back to Japan. In fact, the key to the mystery of the treasure was nearly taken to the grave by Kantora Shimoda, but a small note left to his family in his personal effects provided just the smallest hint to the final resting place of the treasure. Now it is up to you to go and locate it.

(Almost all of this story is factually correct.)