A shipwreck discovered at a site off the coast of Fremantle in Australia is a Dutch submarine that picked up Australian survivors of a Japanese attack during World War II, the Dutch cultural heritage agency has confirmed.

The Hr. Ms. K XI was scuttled at the Rottnest Island ships’ graveyard in 1946 but its final resting place 15 kilometres from the original site, was only discovered at the beginning of January this year.

The Western Australian Museum has since worked on identifying the wreck by comparing archive data with a 3D model of the wreck made by the divers.

“It is the best result we could have hoped for. The discovery of the submarine not only shows the ties between the Netherlands and Australia but also how close we are when it comes to the management of our marine cultural heritage,” spokesman Martijn Manders of the Dutch cultural heritage agency, which helped finance the project, told broadcaster NOS.

The submarine, which was built at the Feijenoord shipyard in Rotterdam in 1925 and originally used to patrol the coast of Indonesia in colonial times, saved the lives of 13 Australian survivors of an attack by Japanese warships in 1942.

“There were just 31 people on board,” Manders said. “It was a K boat, with the K standing for Koloniën (colonies). When the defense of the Dutch Indies as they were then failed, the submarine retreated to Ceylon, where it came under British command. It was also used for training purposes, but by then it was pretty old already,” he said.

The discovery was announced on the 80th anniversary of its final voyage, as it departed the Sri Lankan capital Colombo on February 20, 1945 for the Australian port of Fremantle, where it was decommissioned.

In September 1946, the K XI was scuttled in Rottnest Island, joining over 47 other decommissioned ships at the ship graveyard. The submarine ended up on the edge of the dumping site where, in the absence of any precise data, it was finally located at a depth of just 40m.

Manders said he recommended sports divers have a look at the submarine. “It’s like a big cigar which is slowly being covered in coral. You can even go inside. It’s huge, 31 metres long and 6 metres wide. It’s a fantastic place!” he said.