From haunting shipwrecks to playful marine life, the mysterious beauty of the world underwater has been captured in award-winning detail.
The winners of the 2017 Underwater Photographer of the Year awards have been announced, with entrants hailing from 67 countries submitting 4,500 images into the prestigious competition.
A French photographer, Gabriel Barathieu, took home the Underwater Photographer of the Year 2017 title for 'Dancing Octopus' - a vibrant, close up shot of the creature.
While an enchanting capture of light streaming through the blue Kukulkan Cenote in Mexico won Nick Blake the British Underwater Photographer of Year accolade. He commented: 'My journey from diver to underwater photographer has brought many amazing photographic opportunities and I feel humbled and privileged that this image has achieved such recognition.'
A striking shot of a pod of orcas led to photographer Nicholai Georgiou winning the most promising category.
Other commended shots include a powerful image of silversides at twilight by Tony Myshlyaev and a capture of a gam of whalesharks photographed by Patrick Neumann, who spent 30 years taking 3,000 dives in the hopes of encountering the majestic creature before finally seeing six at once and photographing them.
British Underwater Photographer of the Year 2017 Nick Blake captured light streaming through the Kukulkan Cenote in Mexico. Explaining how he achieved the award-winning shot, he said: 'I left my strobes behind for the natural light shot I wanted and positioned myself in the shadows of the cavern. Moving my eye around the viewfinder, I could see that the rock outline of the cavern around me made for a pleasing symmetry and I adjusted my position to balance the frame. The light show flickered on and off as the sun was periodically covered by cloud and as it reappeared, I beckoned to my buddy and dive guide, Andrea Costanza to edge into the illumination of some of the stronger beams, completing the composition'
Highly commended in the Wide Angle category was this snap entitled Frozen Hunting. Judge Alex Mustard said: 'A stunning behavioural image of a humpback in shallow water scattering herring taken in very tough conditions. The photographer did very well in very dark waters to record this breath-taking scene sharply'
Commended in the Portrait category was this snap of a sealion playing with starfish taken in Los Islotes, Panama
Gabriel Barathieu won the Underwater Photographer of the Year 2017 title for Dancing Octopus, above. The image was taken in the lagoon of Mayotte, in the Indian Ocean, during spring low tides.Judge Alex Mustard commented on the image: 'Both balletic and malevolent, this image shows that the octopus means business as it hunts'
'Green Turtles in the rays' was commended in the portrait category. It was taken during a diving trip to Tenerife
The winner of the British Waters Wide Angle category was this snap taken in the North Sea on the coast of Yell by Melvin Redeker
The wreck of the Louilla on the Gordon Reef, Straits of Tiran, Egypt, was filmed at sunset to win the Wrecks category. The photographer said: 'Beneath her lies a pile of her anchor chains, giving the form of a whale. Wrecks become part of the eco-system in no time'
Commended in the Wide Angle category was a capture of a gam of whalesharks shot by Patrick Neumann (left) who spent 30 years taking 3,000 dives in the hopes of encountering the majestic creatures. This mysterious shot (right) was highly commended in the Wrecks category
An underwater photographer lines up a shot of the conning tower of the wreck of the U-352 off the coast of North Carolina, USA, in this highly commended snap
Highly commended in the Behaviour category, this snap shows a pod of dolphins hunting sardines in South Africa
This photo of a larvae mantis shrimp won the Macro category. Judge, Peter Rowlands said: 'This shot works on so many levels; like a sci-fi encounter in outer space, the fortuitous (for once) backscatter creates a perfect starry background which makes the main subject seem huge and menacing. Perfect composition leaves you in no doubt and you can only fear for the little fella on the right'
This six tonne, six metre whale calf in French Polynesia was 'amazingly playful' explained the photographer who was commended in the Up&Coming category
This stunning image of a humpback whale feeding on krill was taken a few miles offshore from Hout Bay, Cape Town. Photographer Jean Tresfon said: 'Working as part of a film crew, I was privileged to have a chance to photograph this phenomenon. Although the water visibility was really good, inside the krill patch it was much reduced. Without warning the whales appeared just metres away with their pleats distended as they surfaced with huge mouthfuls of krill. Realising that they must be feeding deeper down I descended into the darker water to find the thickest concentration of krill. Suddenly a humpback appeared'
'Silversides at Twilight' was taken on the northern coastline of Koh Tao, Thailand, and was commended in the Wide Angle category
A surreal snap of a freediver was taken in the Philippines and came third in the Up & Coming category (left). A shot of a cave dive was commended in the Wide Angle category (right)
Most Promising British Underwater Photographer 2017 was Nicholai Georgiou who captured this snap of a pod of orcas while freediving in Tromso, Norway
Taken in Sudan at the Umbria wreck this image was highly commended. The photographer said: 'On my way back from the dive, I noticed this room flooded with light. The rays of light streaming down through portholes were lined up so nicely creating a mysterious look of what this room might have looked like when the Umbria was still intact and plying the seas'
'Clownfish Swirl' was shot in Indonesia and commended in the Macro category
This haunting Japanese plane from WWII is a Nakajima B6N 'Jill' Bomber. It was taken in Micronesia and commended in the Wrecks category