An Australian naval search team on Wednesday found the wreck of the country’s first submarine after a 103-year hunt, ABC News reported. The vessel, which the Allies and the Royal Australian Navy used in World War 1, was found 300 metres under water near the Duke of York Islands in Papua New Guinea.

The submarine, HMAS AE1, had 35 crew members on board when it went missing off the coast of the islands in September 1914. As many as 12 previous search expeditions, funded by both the Australian government and private parties, had failed to find the submarine. The 13th and final search began on board the vessel Furgro Equato last week.

“Australia’s oldest naval mystery has been solved,” Defence Minister Marise Payne said. “I truly trust that this discovery will bring peace of mind to the descendants of the families of the crew who lost their lives on board, and perhaps in time, it may also enable us to discover what caused the submarine to sink.”

Australian Navy Chief Vice Admiral Timothy Barrett said the previous expeditions had narrowed down the possible location of the wreck, and improved technology had helped the Navy finally discover it.

Authorities, however, have not revealed the exact location of the wreck because the Australian government is working with Papua New Guinea to preserve the underwater site, ABC News reported.