History regularly reappears along the Danube River near the Serbian town of Prahovo, but it’s likely never been more visible than this summer. As brutal temperatures across much of Europe cause waters to recede to all-time lows, the wrecks of multiple World War II Nazi warships are the most exposed they’ve been in over 80 years. But while the resurfaced vessels speak to both a tragic past and an uncertain future climate, the exposure of an estimated 200 boats is offering local authorities a chance to begin cleaning up a longtime problem stretching back decades.

The story begins in the fall of 1944, as German naval forces attempted to retreat from the Soviet Red Army. To prevent their weapons and vehicles from falling into U.S.S.R. hands, Nazi commanders ordered their soldiers to scuttle any remaining vessels at risk of capture. These included the squadrons sailing on the Danube River, but their plans were more focused than simply sinking their ships as soon as possible. Instead, the Germans strategically placed their boats so that they formed a submerged blockade to prevent the Soviets from progressing upstream.

The underwater barrier of more than 200 barges, cargo ships, and tugs may not have stopped Allied forces in the end, but almost all of the scuttled ships remain where they originally sank. To make matters worse, the abandoned Nazi vessels still hinder trade along that section of the river after more than eight decades. The European Investment Bank (EIB) estimates about $5.75 million in economic losses for Serbia every year related to the blockage.

In 2024, Serbian national authorities began collaborating with the EIB to remove 21 selected shipwrecks along a 3.1-mile-long bottleneck of the Danube during similar receding conditions. Trained crews use specialized pumps to clear the vessels of sediment and mud before towing some of them away, and completely burying larger or more difficult remains to facilitate easier navigation routes. 

However, this project is slow and potentially dangerous work. There’s no way to know if any of the German boats still contain live ammunition or explosives, so each ship identified for removal must first be carefully surveyed by divers. To make things more complicated, the Danube’s murky waters dramatically restrict visibility while examining the sites.

As concerning as it is to see the river reach historically low levels amid record-breaking heatwaves, the increased exposure will likely make the ongoing salvaging process easier and safer for everyone involved. What’s more, the project’s effects will hopefully provide a boost to European Union (EU) climate goals.

“It is an important project for the Green Agenda, too, as it will facilitate the much-needed shift from road to waterway transport,” Emanuele Giaufret, Serbia’s head delegate to the EU, said when the project began.

 

2026 Popular Science Home of the Future Awards

39 products that will improve your everyday life.