A team of maritime archaeologists from the National Cultural Heritage Agency and military personnel from the Royal Netherlands Navy conducted research from 15 June to 1 July 2024 on two submarines sunk in Malaysian waters during World War II. The submarine HNLMS O20 was located where it was expected, but the HNLMS KXVI was recovered illegally.

The expedition was carried out in good cooperation with the Malaysian authorities, who cooperated fully with the mission. Seven crew members died in the loss of the O20. Unfortunately, the submarine KXVI has not been found again, which means that this submarine was illegally salvaged, violating the war grave of its 36 crew members.

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The Netherlands and Malaysia conducted joint maritime archaeological research at the locations of the wrecks of the KXVI and the O20. This involved close cooperation with the Ministries of Defence, Culture and Foreign Affairs of both countries.

The O20 was found at its expected location, but the KXVI was found to have been illegally salvaged. No wreck was found at this location, only excavated soil and remaining iron plates and other objects from both salvage operations and presumably from the submarine.

Previous expedition

An expedition in Malaysian waters in 2019 already found two other submarines, HNLMS KXVII and HNLMS O16, to have disappeared as a result of illegal salvage operations. Even then, the Dutch Cultural Heritage Agency worked constructively with the Royal Netherlands Navy and the Malaysian government.

Martijn Manders, Cultural Heritage Agency’s maritime archaeologist, led both expeditions: ‘Given the previous experience of 2019 and because the KXVI had also disappeared, there was very little hope for the O20. So, we were very happy and surprised to discover that this submarine is still there after all.’

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Iron sought after

The iron from these ships is precious and sought-after. It is of exceptionally high quality because it was manufactured before nuclear weapons exploded into the atmosphere from 1945 onwards. As a result, the iron was not exposed to radioactivity during production and has low background radiation.

Cultural heritage management plan

Discussions will be held with the Malaysian government in the near future on how best to protect the O20 from illegal salvagers. For this, a long-term management plan needs to be drawn up. The locations where the other submarines sank are also still of value as memorial sites. A plan is also being developed for these sites.

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Final resting place

The sunken submarines are the final resting place of those on board. They are war graves. Like five years ago, a memorial ceremony has now also been held by the Dutch expedition members.

The relatives of the fallen soldiers have since been informed of the expedition team’s findings. Another special meeting for the next-of-kin will be organised this autumn.

Picture: A Royal Navy employee controls the underwater robot (ROV) over the O20’s wreck site (photo by Dutch Cultural Heritage Agency/Martijn Manders).