California-based photographer Seth Casteel made his name taking photographs of dogs underwater, but before that, he was snapping cats on land.

Without the use of any type of scuba equipment, divers descend to great depths armed with underwater guns, harpoons and strong line to stalk and hunt prey. Some of the best free-divers in the world can hold their breath for up to 5 minutes under water and go to depths greater than 100 feet.

(All photography © Eyeconic Images.)

These talented turtles have been "snapped" performing for the camera as they practice their synchronized swimming routine. Photographed underwater by Monste Grillo, 36, from Tenerife, Spain, the turtles are seen swimming in unison as well as touching fins as they circle towards the surface. After spending hours in the water off the coast of the Canary Islands in 2012, the photographs capture the gentle nature of the creatures as well as giving a fascinating glimpse into their behavior in the wild. (CATERS NEWS)

A thrill-seeking photographer risked life and limb as he swam alongside a ten-foot-long American crocodile near Belize. Stunning pictures show Mexican underwater photographer Rodrigo Friscione getting up close and personal with the two-hundred-pound predator. (Photo by Rodrigo Friscione/Mediadrumwor.com)

This undated handout picture taken by Tim Samuel and provided through his Instagram account shows a small fish swimming inside the belly of a jellyfish off the coast of Byron Bay in New South Wales, eastern Australia. A fish has been pictured swimming inside a jellyfish off Australia's east coast in a remarkable and rare image that has gone viral, with more than two million online views. Underwater photographer Tim Samuel was in the water with a friend near popular tourist resort Byron Bay in December when they came across the little creature trapped inside the only slightly larger jellyfish. (Photo by Tim Samuel Photography/AFP Photo/Instagram)

Chinese women run with a ball on a snow covered field in Shenyang in China's northeastern Liaoning province during International Women's Day on March 8, 2018. International Women's Day is celebrated on March 8 every year and commemorates the movement for women's rights. (Photo by AFP Photo/Stringer)

Yin and yang. Sеxy women grey background. Sensual women in erotic lingerie. (Photo by Alamy Stock Photo)

Project Mermaids model. Project Mermaids lets ocean-lovers don tails and live out their siren fantasies. Clients can pay for a shoot that is either on land or underwater, with the images looking to raise awareness about preservation of beaches, seas and oceans. The project – which is shot by photographers Angelina Venturella and Chiara Salomoni – started purely to raise awareness, with celebrities dressing up as sirens as part of the cause. (Photo by Angelina Venturella/Chiara Salomoni/Caters News Agency)