A German chemistry professor started on Monday a gruelling four-week solo swim down the Rhine river for the benefit of science and the environment.
Self-confessed "mad professor" Andreas Fath, who set off on his 1,231-kilometre (764-mile) adventure with a splash into Switzerland's Lake Toma, plans to swim through Germany and France to reach the river's mouth at the Dutch port of Rotterdam on August 24.
Sponsorship money raised by Fath's 25-day journey will pay for a high-tech water analysis instrument worth over 100,000 euros ($130,000) for his University of Furtwangen with which he aims to test samples from the Rhine for pollutants.
Days before setting off, and after training for more than a year, Fath, 49, told AFP that he wanted "to show everything that's in the Rhine" and find out where contaminants originate so they can be stopped.
Water samples will be tested for industrial chemicals, hormones, pharmaceuticals, pathogens and microscopic plastic parts, according to his website www.rheines-wasser.eu.
Fath, a married father of three from the southwestern state of Baden-Wurttemberg, said he started swimming at age eight and has taken a dip almost every day since.
"That's where I relax, that's where I'm weightless and in my own world," he said. "That's where I'm able to switch off in a wonderful way."
In 2008 he swam 27 kilometres across Lake Zurich, taking six hours and 17 minutes, a record time in his age group, he said.
Despite his years of experience, he said he respects the Rhine for the tough challenges it will throw at him, including the "headache" of rocky stretches in the upper reaches and the "sporting challenge" of swimming 40 kilometres across Lake Constance.
Explore further: Image: Lake Constance in Central Europe from the Sentinel-1A satellite