An intimate photo of an octopus swimming through shallow waters earned underwater photographer Gabriel Barathieu the Underwater Photographer of the Year award for his photo "Dancing Octopus." Barathieu's winning photograph was taken in a lagoon off the coast of the small island Mayotte in the Indian Ocean.

"The way it moves is so different from any predator on land," said competition judge Alex Mustard. "This truly could be an alien from another world.

Barathieu exercised an immense amount of patience to wait for the right shot, saying: “I had to wait for a low spring tide when the water was just 30cm deep (1 foot) so that the octopus would fill the water column. I got as close as possible with a wide angle lens to create this image, which makes the octopus look huge.”

Over 4,500 photographs from 67 different countries were entered into this year's contest. The competition is held by UPY London, which consists of judges experienced in underwater photography who convene to recognize the best in their field. This year's panel consisted of photographers Martin Edge, Alex Mustard, and Peter Rowlands, the latter of whom has published photos in National Geographic magazine. The contest was created as an offshoot of the British Society of Underwater Photographers, and thus has award categories specifically allocated for British citizens.

Photographer Nick Blake received the prestigious British Underwater Photographer of the Year award for this photo "Out of the Blue," taken in a freshwater sinkhole in Mexico. The sinkhole, Chac Mool Cenote, produced a spectacular light effect as the sun lit and reflected off the dark waters.

Blake said of his approach: "Underwater photographers can move freely in three dimensions, so I adjusted my position in the water to capture the symmetrical framing of the light beams by the rocks."

"I love the enclosure of the light within the cenote," said competition judge Martin Edge. "The composition contains all the sunlight so that the eye of the viewer cannot escape."

The contest's Up and Coming Underwater Photographer and Most promising British Underwater Photographer of the Year awards went to Horacio Martinez and Nicholai Georgiou respectively.

Several other photographers were recognized in the contest's other categories of wide angle, macro, wrecks, behavior, portrait, compact, and British waters wide angle. Winning images displayed a variety of underwater scenes from an intimate photo of a whale and her calf, to the wreckage of an aircraft sunk during WWII.