The Weser Ultra: a marathon swim down the River Weser

Para-swimmer and world champion ice swimmer Tina Deeken and her swimming partner Tobias Prüßner have completed a 50km self-supported swim down the River Weser, Germany, to protest against the continued salinisation of the river.

In 2021-2022, Tobias Prüßner (non-disabled) and para-swimmer and world champion ice swimmer Tina Deeken completed a 202km swim down the Upper Weser river from the ‘source’ in Hann. Münden to Minden, Germany. 

They created the ‘Weser 200’ swim, which was undertaken in stages self-supported and without an escort boat, to draw attention to the problem of salinisation of the River Weser caused by saline wastewater being discharged into the water.

In 2023, they decided to further the cause by undertaking a long inclusive marathon swim, again self-supported and without an escort boat, which they called the ‘Weser Ultra’, swimming 50km from Großenwieden to Minden in 9 hours on 19 July 2023.

The risks and joys of swimming in the Upper Weser

“Tobias is the ideas man and organised the logistics,” Tina told us following their swim. “We swam all alone without an escort boat. We both had a buoy with us for better visibility. Tobias also pulled a bodyboard with my orthoses and poles behind him, as well as a small waterproof barrel with food.”

The conditions on the day were not easy, with a headwind of around force 3-4; the water temperature was 21°. The level of the Weser was not too high, so the current was not so strong. Swimming in the Upper Weser brings with it many dangers. Risks include passing ferries, dredger ships, excursion boats, water-skiers and bridge construction sites.

Tina said one of the highlights on the route was swimming past the Kaiser Wilhelm Monument in Porta-Westfalica. “There was not much else going on at and on the Weser that day, but that meant we could enjoy the nature: fields, meadows, forests, cliffs, mountains. We saw herons, fish, ducks and cows.” 

Although it was their second challenge swimming down the Weser, the river still had wisdom to impart. “We learned on the day of swimming in the Weser that every swim in the river is different, depending on the level, flow conditions, weather, season and perspective,” said Tina. 

Efforts are ongoing to draw awareness to and stop the salinisation of the Weser and Werra, with contamination from chlorides, caused by local potash mining, severely polluting plant and animal life in the water. “The guidelines for salt discharge have been adjusted downwards since last year, but salinisation still threatens the ecosystem of the river as well as the adjacent nature,” Tina told us. 

“Environmental protection is an important issue for all open water swimmers. Next, we are planning to swim another small section of the Middle Weser, but this will be more difficult due to weirs and locks and industrial shipping. And we will certainly come up with an interesting swimming campaign for 2023 on the Upper Weser to keep drawing attention to salinisation.”

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Jo is the Gear Editor for Outdoor Swimmer and also writes news and features for the website. A keen open water swimmer and long-distance walker, she loves seeking out lakes and lidos close to her home in the Mendip Hills, Somerset. She is the author of The Slow Traveller, editor and founder of independent magazine, Ernest, and has previously tested outdoor clothing and kit for BBC Countryfile Magazine, BBC Focus and Ernest Journal.