Surfer Arlen Macpherson sits on his board, which has an electronic shark repellent device installed, at Sydney's Bondi Beach in Australia, August 18, 2015. A spate of shark attacks in Australia has left some of world's top surfing beaches deserted and many people having second thoughts about taking a swim as the summer approaches. Macpherson paid A$390 for a device embedded in his surf board to repel sharks by emitting an electronic force field that overpowers its sensing organs. (Photo by David Gray/Reuters)

A swimmer competes in Le Defi Monte-Cristo (Monte Cristo Challenge) swimming event at the Chateau d'If, off the coast of Marseille, southern France, on June 21, 2019. Created in 1999 and inspired by Alexandre Dumas' character of Edmond Dantes, the Monte Cristo Challenge will take place from June 21 to 23, 2019. (Photo by Boris Horvat/AFP Photo)

“Secrets of the Whales”. Skerry’s photographs celebrate the lives and culture of whales, illuminating recent research and their diverse behaviours. His latest work focuses on four key species: sperm whales, humpbacks, orca and beluga whales. Humpback whales bubble-net feeding off the coast of Alaska. They work cooperatively to feed on herring by blowing a perfect ring of bubbles underwater to form a net encircling the fish. The whales then swim up through the centre of the bubble net with their mouths open. (Photo by Brian Skerry/National Geographic Photo/Visa pour l'Image)

Rocky the cat's recovery from a nerve condition in his legs is coming along swimmingly – thanks to regular hydrotherapy sessions at a 20ft-long swimming pool in United Kingdom in the second decade of March 2022. The two-year-old wears a life vest to help keep him afloat and needs a plastic toy to lure him from one end of the pool to the other. (Photo by Max Willcock/BNPS Press Agency)

AP photographer Anja Niedringhaus laughs as she attends a swimming event at the 2004 Olympic Games in Athens, August 21, 2004. Niedringhaus, a veteran Associated Press photographer who had covered wars around the world was shot dead and another reporter was wounded on April 4, 2014 when an Afghan policeman opened fire on them in eastern Afghanistan, the news agency said. (Photo by Reuters/Staff)

A dog swims as a resident navigates his boat in a neighbourhood flooded by the Purus river, which continues to rise from days of heavy rainfall in the region, in Boca do Acre, Amazonas state March 14, 2015. According the state civil defense, more than 20,000 people have been left homeless along the Purus river, where incessant rains have flooded the area and caused the river to burst their banks. (Photo by Bruno Kelly/Reuters)

In this May 8, 2015 photo, sisters Zoraida Infante, left, and Graciela Trujillo pray on Fishermen's Beach before therapeutic swimming in the Pacific Ocean in Lima, Peru. Under overcast skies, the bathers practice thalassotherapy, which derives from the Greek “thalasso”, for “sea”, and draws on the ocean's healing properties. (Photo by Rodrigo Abd/AP Photo)

Underwater photographer of the year 2020 and wide angle category winner: Frozen Mobile Home by Greg Lecoeur (France) in the Antarctic peninsula, Antarctica. Crabeater seals swim around an iceberg. These massive and mysterious habitats are dynamic kingdoms that support marine life. As they swing and rotate slowly through polar currents, icebergs fertilise the oceans by carrying nutrients from land that spark blooms of phytoplankton, fundamental to the carbon cycle. (Photo by Greg Lecoeur/Underwater Photographer of the Year 2020)