A new trove of sunken Nazi ships has emerged in the River Danube, following a blistering summer drought that caused water levels to drop, according to new reporting by Reuters. 

The German vessels, still decked out with explosives, were discovered by the Serbian town of Prahovo. Hundreds of miles up the river, receding water revealed four other ships by Hungary’s Danube-Drava National Park. This set of vessels was from before 1950, the outlet said.

This isn’t the first time ships have cropped up in the River Danube, Europe’s second-longest river at 1,770 miles. Perennial droughts and heat waves have led to drastic drops in water levels each year, exposing German ships while simultaneously threatening the drinking supply and frustrating navigators weaving their way down the water route that stretches from the Black Forest in southwestern Germany to the Black Sea in eastern Romania.

“Captains must be extremely cautious and incidents such as grounding frequently occur,” Damir Vladic, the manager of the port of Prahovo, told AFP. “It only takes a slight deviation from the navigable route to cause problems.”

Dozens of scattered ships operated by Nazi Germany’s Black Sea fleet appeared in 2022 near Prahovo after water levels reached record lows. That year, the Copernicus program, managed by the European Commission, documented the water scarcity along the Danube and said certain parts of the river in western Europe were unnavigable. 

The lowest level recorded in the Danube was 1.3 feet in October 2018, according to Reuters. On Tuesday, the Danube measured 3.8 feet high by Budapest, the outlet said.

How the Nazi ships ended up stuck in the Danube

Nazi Germany and its allies occupied the Western Balkans from 1941 to 1945, where they imposed an iron-fisted rule and fought communist partisan guerillas.

But following the disastrous invasion of the Soviet Union, German forces were steadily driven back to its borders.

As Nazi troops retreated west, Germany scuttled scores of ships from its Black Sea fleet across the Danube in September 1944. The aim was to slow the Red Army by clogging the river, but also to prevent the vessels from falling into Soviet hands.

“The Germans were retreating from the Red Army,” said historian Velimir Miki Trailovic.

“They wanted to pass through the Djerdap Gorge,” he added, referring to a nearby narrow river pass. “But when they realized they couldn’t, they decided to scuttle the ships.”

The Nazis sank nearly 200 vessels during their retreat, including transport ferries, barges and torpedo boats, according to Trailovic.

Clearing the river of the WWII boats

For 80 years, the boats remained largely undisturbed on the bottom of the Danube. During droughts, the hulking steel hull of a German tugboat marked UJ-106 pierced the surface near Prahovo.

A 2022 initiative financed by the European Investment Bank and Western Balkans Investment Framework has provided nearly 30 million euros to oversee a salvage operation to remove the crafts.

The first ship —a minesweeper— was pulled from the Danube in August. Local port workers even suggested the vessel could be relaunched after patching up its holes and extensive cleaning.

But removing the ships is complicated by the submerged munitions buried with them, which require careful maneuvering to avoid any risk of detonating them.

“The ships are full of mines, shells and unexploded ordnance, which could cause major, catastrophic problems if they were to explode,” Trailovic told AFP.

Serbian officials estimate it will take a year and a half to remove the ships.

“In the coming months, we will retrieve 21 ships that have been lying on the bottom of the Danube,” said Goran Vesic, Serbia’s minister of construction, transportation and infrastructure.