An athlete dressed as a clown jumps into the Mediterranean sea as he takes part in the Copa Nadal in the Spanish port of Barcelona in Barcelona, Spain, Sunday, December 25, 2016. The Copa Nadal (Christmas Cup) is a traditional swimming competition that takes place in Barcelona every December 25th, where participants swim 200 meters in the open sea in the port of Barcelona. (Photo by Manu Fernandez/AP 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)

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)

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)

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)

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 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)

A man walks past kelp as he goes for a swim in the Pacific Ocean at La Jolla Shores, Thursday, July 24, 2025, in San Diego. (Photo by Gregory Bull/AP Photo)