A Dresden resident swims across the Danube from its source to its mouth

Joseph Heß, an extreme swimmer from Dresden, has swum the entire length of the Danube, from its source in Donaueschingen to the Black Sea. After nearly 60 days, he reached his destination in Sulina on Tuesday, his team reported. He began the final day in the morning in Crișan, in the heart of the Danube Delta, and then covered another 30 kilometers. During the journey, Heß crossed through ten countries. “That was the greatest adventure of my life and the longest river stretch I’ve ever swum,” he emphasized.

Extreme swimmer is now looking forward to seeing his family

“It was wonderful, but for now I’m also just glad it’s over. I’m looking forward to seeing my family at home,” Hess admitted. “My shoulders have been bothering me every day, and I can barely lift my arms above my head, but otherwise I’m doing very well. Luckily, I didn’t get sick along the way.”

Documentary on environmental pollution and the effects of climate change

According to his support team, the route also took him along the Romanian-Ukrainian border in recent days. Merchant ships were protected from drone attacks with nets, and they observed destroyed industrial facilities and explosions from a distance. Hess was accompanied by filmmaker Markus Weinberg. “At the same time, we documented how low water levels, environmental pollution, shipping, history, and the impacts of climate change intersect along an entire European river,” Weinberg explained. 

Low water levels revealed shipwrecks

Hess swam through Vienna, Bratislava, Budapest, and Belgrade, as well as through the spectacular Iron Gate—a valley in the Carpathians about 100 kilometers long. “Historically low water levels caused tributaries to dry up and sandbars and islands to form. Near Prahovo, wrecks of German warships from World War II emerged from the Danube,” the report stated. The stretch through Belgrade had become a health hazard due to heavy sewage pollution. The team described it as a “river in a state of emergency.”

Team Collected Water Data for Scientific Research

Water samples were taken regularly along the entire route according to scientific guidelines. The data will be used to create a microplastic map of the Danube, the report continued. Initial analyses showed no uniform contamination, but rather individual hotspots—including areas near wastewater treatment plants and tributaries. The complete scientific analysis will follow after the expedition.