Seth Casteel is an award-winning photographer and the New York Times Best Selling Author of Underwater Dogs. His new book, Underwater Puppies, was published September 16, 2014. Photo: “Underwater Puppies”: Popcicle. (Photo by Seth Casteel)

A life-size sculpture of a pianist, made of approximately 210,000 matches and weighs around 100 kilograms, is seen in Tomislav Horvat's studio in Podturen, Croatia, October 27, 2016. For the last ten years, Horvat has built sculptures made from matches. This is his biggest sculpture to date that took him some 30 months to build. (Photo by Antonio Bronic/Reuters)

Opera singers perform in the pool “AquAria PALAOA” during a rehearsal at the swimming pool Neukoelln on April 27, 2011 in Berlin, Germany. The premiere of the underwater opera AquAria PALAOA is on May 1st. (Photo by Andreas Rentz/Getty Images)

The rarely seen blue sharks photographed by Saeed Rashid in British waters. Elusive blue sharks have recently been spotted off the south coast of England, having moved to the UKs warmer waters to hunt. The carnivorous sharks have been lurking off the coast of the popular British holiday destination, Penzance, in Cornwall. (Photo by Saeed Rashid/Caters News)

Open jaws of a Great White Shark Carcharodon Carcharias, South Africa. (Photo by Stephen Frink Collection/Alamy Stock Photo)

“In 2009 a monumental underwater museum called “MUSA” (Museo Subacuático de Arte) was formed in the waters surrounding Cancun, Isla Mujeres and Punta Nizuc. The project founded by Jaime Gonzalez Cano of The National Marine Park, Roberto Diaz of The Cancun Nautical Association and Jason deCaires Taylor consists of over 450 permanent life-size sculptures and is one of the largest and most ambitious underwater artificial art attractions in the world”. – UnderwaterSculpture (Photos by Jason deCaires Taylor/Intrepidacious/Kozy and Dan Kitchens)