People on inflatable boats enjoy the weather on the Lake Lucerne in Sisikon, Switzerland, August 5, 2018. (Photo by Denis Balibouse/Reuters)

A boat is stranded on Poyang Lake in Lushan City, China during low-water season on November 3, 2016. (Photo by Xinhua/Barcroft Images)

People ride a boat on the Tianquan Lake during a foggy day in Xuyi in China's eastern Jiangsu province on November 20, 2019. (Photo by AFP Photo/China Stringer Network)

In this aerial view fishing boats are seen on the shore of the Lake Malawi at the Senga village on May 20, 2019 in Senga, Malawi. Hundreds of local traders gather each morning and afternoon at Senga, but fish populations are falling in Lake Malawi, Africa's third largest body of freshwater. (Photo by Gianluigi Guercia/AFP Photo)

Growing cities, overuse of fertilizers and factory wastewater have degraded China's water supplies to the extent that half the nation's rivers and lakes are severely polluted. China aims to spend $850 billion to improve filthy water supplies over the next decade, but even such huge outlays may do little to reverse damage caused by decades of pollution and overuse in Beijing's push for rapid economic growth. Photo: Fishermen row a boat in the algae-filled Chaohu Lake in Hefei, Anhui province, June 19, 2009. (Photo by Jianan Yu/Reuters)

Costumed participants of a lacquer and leather ship, the so-called “Torture Ship”, kiss before putting out to Lake Constance for a pleasure cruise at the harbor of Friedrichshafen, Germany, 29 June 2019. Hundreds of leather and rubber fans set sail for the boat trip through the night on Lake Constance. (Photo by Daniel Kopatsch/EPA/EFE)

Aerial view of a boat working in the green water of Taihu Lake covered by blue-green algae, Wuxi city, Jiangsu province, China on May 23, 2018. (Photo by Imaginechina/Rex Features/Shutterstock)

Houseboats and charter boats are docked in the ice in the harbor at Fischerhof Eldenburg in the Mecklenburg Lake District, northern Germany, Wednesday, February 19, 2025. (Photo by Jens Büttner/dpa)