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)

Ace Wu searches the deep to photograph stunning underwater creatures. Against their predominantly black backdrops, Wu’s breathtaking subjects glow with sublime vibrancy. In one, a fearsome fish glares at the camera with rows of sharp teeth showing, while in another, a translucent octopus looks like an extraterrestrial. Here: Wunderpus larva. (Photo by Ace Wu/Caters News Agency)

Impressive images of these alien-like creatures were captured underwater – photographer Cai Songda is a keen diver and did not miss the chance to snap pictures of the unique “aliens”. Here: A Tremoctopus Gracilis in the waters around Anilao, Philippines. (Photo by Cai Songda/Caters News Agency)

Underwater photographer Sarah Lee uses a technique known as “duck diving” to capture these stunning photos of surfers in Hawaii. Surfers “duck dive” under the water to avoid incoming waves so they can get further out to sea. Photo: A surfer comes free from her surfboard. (Photo by Sarah Lee/Caters News)

“Secrets of the Whales”. Skerry’s photographs celebrate the lives and culture of whales, illuminating recent research and their diverse behaviours. His latest work focuses on four key species: sperm whales, humpbacks, orca and beluga whales. Humpback whales bubble-net feeding off the coast of Alaska. They work cooperatively to feed on herring by blowing a perfect ring of bubbles underwater to form a net encircling the fish. The whales then swim up through the centre of the bubble net with their mouths open. (Photo by Brian Skerry/National Geographic Photo/Visa pour l'Image)

These images show the unique bond a group of free divers formed with gigantic sperm whales. Swimming just inches away from the huge mammals, the divers are dwarfed in size, made to look like specks in comparison. The photos were taken by renowned underwater photographers Alexandre Roubaud and Alexandre Voyer, who are based in Paris but travel the world to capture such stunning imagery. Here: a diver with a sperm whales. (Photo by Alexandre Roubaud/Alexandre Voyer/Caters News)

In this undated photo provided by LittleFriendsPhoto.com via Six Flags Discovery Kingdom, Kai, a 17-year-old male California sea lion at Six Flags Discovery Kingdom in Valejo, Calif. peers into the lens of photographer Seth Casteel, known for his “Underwater Dogs” photo series. ... (Photo by Seth Casteel/AP Photo/LittleFriendsPhoto.com via Six Flags Discovery Kingdom)

These photographs appear to show a spectacular underwater world making it ideal for scuba divers – in central Europe. Twelve metres of water covers trees, footpaths, benches and bridges that are usually accessible throughout the year. Visitors to the Green Lake in Tragoess, Austria, that is normally only one metre deep, can leisurely stroll around the picturesque lagoon. Photo: A diver crossing a bridge in the flood water. (Photo by Solnet/The Grosby Group)