Wide-angle category winner. Part of the Illusion by Marcus Blatchford (UK). Location: National Dive & Activity Centre, Chepstow, Wales. “This is the deepest inland dive centre in the UK. The dive plan was to explore the deep end, but this time I dived ‘unplugged’ (without my strobes). With the exception of this change to my camera technique, there were no planned shots I wanted to achieve – just a fun dive with ad-hoc photos along the way. Shortly after this photo was captured, in 6C water and two hours of decompression ahead of us, we turned and started the long ascent back to the surface”. (Photo by Marcus Blatchford/Underwater Photographer of the Year 2016)

Scuba divers during an ice diving class at the Sea Frogs scuba diving center in the Russian Far Eastern city of Vladivostok on January 30, 2022. The air temperature is –11°C (12.2°F), the water temperature is –2°C (28.4°F). Scuba divers undergo theoretical and practical training in ice diving and perform dives in the open water during the day and the night time as part of the Ice Diver NDL special program. (Photo by Yuri Smityuk/TASS)

British holidaymaker Sean Chinn captures a crocodile on camera during a dive at the Jardines de la Reina marine park in Caribbean Sea, Cuba. (Photo by Sean Chinn/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)

Rescuers pull dead whales ashore in Probolinggo, East Java, Indonesia, Thursday, June 16, 2016 during a mass rescue operation of stranded whales. Most of more than 30 stranded whales were managed to be pulled into the deep sea, an official said. (AP Photo/Trisnadi)

Photographer Mark Tipple captured the underwater pictures with his friend Mike as the surfer. But the rough waves of the coast of the Cook Islands slammed Mike into the sea bed during the shoot, causing him to slice his skin open and badly bruise his body. Photo: Mike diving beneath a shallow wave. (Photo by Mark Tipple/Caters News Agency)

People run into the sea at the beach of Scheveningen on New Year's Day, Scheveningen, Netherlands, 01 January 2023. The traditional New Year's dive was resumed after the two previous editions were canceled due to the corona crisis. (Photo by Remko de Waal/EPA/EFE/Rex Features/Shutterstock)