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)

Will Rosner and a playful humpback whale pose for a selfie. This man is certainly knows how to enjoy life travelling the South Pacific and posing for selfies with a whale. Australian carpenter Will Rosner, 24, from Sydney, Australia, has been travelling the world for the past 18 months but nothing could have prepared him for this incredible postcard moment. Swimming in the pristine waters of the Tonga in the Pacific Ocean Will was lucky enough to have the chance to swim with an entire pod of humpback whales. (Photo by WIll Rosner/Caters News)

A stranded cat swims through flood water searching for dry land June 16, 2008 in Oakville, Iowa. (Photo by Scott Olson/Getty Images)

A duck swims in a Osterbekkanal during a the rainy autumn afternoon, central Hamburg, Germany 20 November 2017. (Photo by Srdjan Suki/EPA/EFE)

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)