Officials still haven’t found MH370, the Malaysia Airlines plane that disappeared nearly two years ago while en route from Kuala Lumpur to Beijing. However, searches for the aircraft have unintentionally detected two shipwrecks: a cargo vessel that’s submerged 12,100 feet near the Australian port of Fremantle, as well as a similar ship that was confirmed as a recovered wreck in May.

According to the Associated Press, the most recent shipwreck was first detected on December 19 via sonar technology. Searchers used an underwater drone to take pictures of the debris, and archaeologists examined the shots. They determined that the ship, probably made of steel or iron, likely sank in the 19th century.

It’s too expensive to identify the ships, but they do offer a silver lining for search parties. According to Peter Foley, director of the operational search for MH370, finds like these show that “the systems, people and the equipment involved in the search are working well. It’s shown that if there’s a debris field in the search area, we’ll find it,” The Guardian quoted Foley as saying last spring.

[h/t Associated Press]