In pictures: whales, dolphins and dugongs
The Wildlife Photographer of the Year exhibition showcases the world's best nature photography.
It takes technical skill and an understanding of the natural world to create a winning image.
Take a tour of wildlife photography highlighting some of the most captivating creatures beneath the waves.
For the artful shot above, Audun's goal was to contrast the stillness above the water with the humpback's playfulness just below. With their wide, powerful tails and long flippers, these 40-tonne animals easily launch themselves out of the water.
Two juvenile golden trevallies ride the pressure waves created by a dugong swimming in the Red Sea.
They use the tranquil mammal as protection from predators and feed on the small creatures it disturbs.
An imposing Bryde's whale rips through a mass of sardines, gulping hundreds in a single pass. This scene is from the annual sardine run, when billions of sardines migrate along South Africa's Wild Coast.
Wim's fortuitous shot captures the moment a mass of bottlenose dolphins explode out of a curtain of sparkling ocean spray. Some scientists argue that dolphins don't play for the sheer fun of it in the way we humans do.
However, what Wim observed that day off Port St Johns, South Africa, suggests otherwise.
False killer whales are cautious and seldom approach divers, so close-up photos are rare. Scientists have long known that bottlenose dolphins associate with false killer whales, but this is almost certainly the first time the relationship has been captured on camera.
Douglas encountered this feeding dugong in a sheltered bay along the Egyptian coast, vigorously sucking up seagrass (its principal food) and moving itself along on its flippers rather than its whale-like tail, which it uses for swimming.
According to Douglas, local dive operators had given this particular individual the nickname Dyson on account of his powerful vacuuming technique.
United in their hunt for herring, whales and fishermen off the coast of Norway have a symbiotic but risky relationship. Fishermen use killer whales to find fish, and in turn the whales seek out fishing boats hoping to land a free meal.
However, things don't always run smoothly, with whales frequently entangling themselves in the nets with fatal consequences. Audun captures this unusual relationship in a dramatic split-level picture.
Brian captured this pod of spinner dolphins at rest in the waters off northwest Oahu, Hawaii. Spinners are well known for their acrobatics, leaping up to three metres out of the water and completing as many as seven revolutions in the air before plunging again.
It is not certain why they do this, though it may be for communicating or to dislodge remoras, or suckerfish, from their bodies.
Meet Migaloo (which means 'white fella'), who happens to be the only known all-white humpback whale in the world.
This portrait was taken from a helicopter and captures the elusive moment of the humpback rising to the surface to breathe before disappearing into the depths. This shot was taken in the Coral Sea off Green Island, Australia.
To learn more about the fascinating world of whales, visit the exhibition Whales: Beneath the surface.