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 squid swims underwater off the shore of the coastal city of Qalamun, north of the Lebanese capital Beirut, on September 24, 2019. (Photo by Ibrahim Chalhoub/AFP Photo)

Members of the Coney Island Polar Bear Club warm up before swimming at the beach at Coney Island in New York, December 15, 2013. (Photo by Eric Thayer/Reuters)

Lucy Blacker from Australia takes to the water at the 40 Foot for a Christmas Day Swim in Ireland on December 25, 2022. (Photo by Alan Betson/The Irish Times)

Team China performs during the team free routine artistic swimming competition at the 19th Asian Games in Hangzhou, China, Sunday, October 8, 2023. (Photo by Aaron Favila/AP Photo)

A wild water monitor (Varanus salvator) is seen swimming between colorful popcorn snacks at a Lumphini public park in Bangkok, Thailand on March 27, 2022. (Photo by Matt Hunt/Neato/Rex Features/Shutterstock)

A diver dressed in a Santa Claus costume swims with a penguin at Sunshine Aquarium during preparations for the upcoming Christmas special event in Tokyo on December 1, 2025. (Photo by Kazuhiro Nogi/AFP via Getty Images)

A puffin swims underwater in search for fish off the coast of the Farne Islands in Northumberland, North East England in the last decade of July 2025. (Photo by Brian Matthews/Solent News & Photo Agency)