Members of Brighton Swimming Club brave the early morning temperature to take a dip in the sea east of the pier on January 5, 2022. The club, founded in 1860, is the oldest in England. (Photo by Simon Dack/Alamy Live News)

Team Japan competes during the team free preliminaries of artistic swimming at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (Photo by Anna Szilagyi/AP Photo)

This photo taken on November 7, 2023 shows winter swimming enthusiasts taking photos at Beiling Park after snowfall in Shenyang, in China's northeastern Liaoning province. (Photo by AFP Photo/China Stringer Network)

A person dressed as Santa Claus jumps into the sea during the Copa Nadal (Christmas Cup) swimming race in Barcelona, Spain on December 25, 2024. (Photo by Bruna Casas/Reuters)

Australia’s Hannah Fredericks competes in the women’s 200m backstroke heats during the Australian Swimming Trials at the Brisbane Aquatic Centre on June 13, 2024. (Photo by David Gray/AFP Photo)

This aerial view shows youths swimming to cool off in the waters of Iraq's Euphrates river during a heatwave, in the district of al-Hindiyah east of Karbala on June 7, 2024. (Photo by Karar Jabbar/AFP Photo)

Divers swim beside millions of silverside fish at Devil's Grotto, Cayman Islands. Swimming in unison, millions of silverside fish dwarf the divers. The fish create waves of silver light as they move around the grottos that lie beneath the surface of the Caribbean Sea. These amazing photographs were captured by Belgian photographer Ellen Cuylaerts, 44, on a diving trip to the Devil's Grotto, Cayman Islands. (Photo by Ellen Cuylaerts/This is Guavo Media)

A swimmer stops short of a red algae bloom at Sydney's Clovelly Beach on November 27, 2012, which closed some beaches for swimming including Bondi Beach for a period of time. While the red algae, known as Noctiluca scintillans or sea sparkle, has no toxic effects, people are still advised to avoid swimming in areas with discoloured water because the algae, which can be high in ammonia, can cause skin irritation. (Photo by William West/AFP Photo)