People swim underwater at Clovelly Beach on December 14, 2023 in Sydney, Australia. A severe heat wave hit Sydney over the weekend, a precursor of hot and dry conditions expected for the rest of the summer which will also bring heightened bushfire risk. The mercury rose to alarming levels again on Thursday. (Photo by Jenny Evans/Getty Images)

Zoi Karangelou of Greece compete in the Women's Solo Technical final on day one of World Aquatics Artistic Swimming World Cup Super Final 2025 at Xi'an Olympic Sports Centre on June 13, 2025 in Xi An, China. (Photo by Lintao Zhang/Getty Images)

Trainers from Tianjiao Special Guard/Security Consultant Ltd. Co. engage trainees dressed in swimming suits as they crawl on the beach during a training session in Sanya, Hainan province January 8, 2012. (Photo by CHINA DAILY/Reuters)

This undated handout picture taken by Tim Samuel and provided through his Instagram account shows a small fish swimming inside the belly of a jellyfish off the coast of Byron Bay in New South Wales, eastern Australia. A fish has been pictured swimming inside a jellyfish off Australia's east coast in a remarkable and rare image that has gone viral, with more than two million online views. Underwater photographer Tim Samuel was in the water with a friend near popular tourist resort Byron Bay in December when they came across the little creature trapped inside the only slightly larger jellyfish. (Photo by Tim Samuel Photography/AFP Photo/Instagram)

A group of people wearing Santa Claus hats and swimming suits participate in the 13th charity Great Santa Claus Run in downtown Budapest, Hungary, Sunday, December 11, 2016. (Photo by Balazs Mohai/MTI via AP Photo)

Yanna Xian, 24, and her boyfriend Mitch Brown, 27, were swimming while on a boat tour off Honolulu, Hawaii last year, when a curious two-week-old humpback approached them. (Photo by South West News Service)

Nicolo Martinenghi of Italy competes in the Men's 50m Breaststroke Final on day six of the 2022 FINA World Short Course Swimming Championships at Melbourne Sports and Aquatic Centre on December 18, 2022 in Melbourne, Australia. (Photo by Daniel Pockett/Getty Images)

Team Spain perform their routine during the Team Technical during the World Aquatics Artistic Swimming World Cup 2024 - Stop 2 at Aquatics Centre on May 03, 2024 in Paris, France. (Photo by Adam Pretty/Getty Images)