Teeming with images of spectacular underwater scenes from around the world, Call of the Blue is the culmination of a five-year project by the photographer and ocean conservationist Philip Hamilton. This groundbreaking book includes contributions from acclaimed scientists and ocean “guardians”, who reveal what drove them to answer the call of the blue. (Photo by Philip Hamilton/The Guardian)

Syrian refugees sit behind barbed wire as they wait to cross into Macedonia at the Greek-Macedonian border, near the village of Idomeni, August 21, 2015. (Photo by Yannis Behrakis/Reuters)

A muddied family photograph sits on a hallway stairwell in an apartment block on March 17, 2011 in Kensennuma, Japan. Residents were allowed back to their homes today and began the massive cleanup operation caused by a 9.0 magnitude strong earthquake that struck on March 11 off the coast of north-eastern Japan. The quake triggered a tsunami wave of up to 10 metres which engulfed large parts of north-eastern Japan. The death toll has risen past 5000 with at least 8600 people still missing. (Photo by Chris McGrath/Getty Images)

Santa Claus poses with a Beluga Whale at SeaWorld San Diego on December 15, 2011 in San Diego, California. (Photo by Mike Aguilera/SeaWorld San Diego via Getty Images)

A drone view shows people surfing during spring sunshine, as the warm weather is set to continue into the weekend, at Fistral Beach, Newquay, south west Britain, on May 9, 2024. (Photo by Toby Melville/Reuters)

Swimmers in fancy costume take part in the New Year's Day swim at Saundersfoot in Wales, Britain, January 1, 2017. (Photo by Rebecca Naden/Reuters)

Underwater photographer of the year – winner. Dancing Octopus by Gabriel Barathieu (France). Location: Island of Mayotte, off the coast of south-east Africa. “Balletic and malevolent”, one judge said of this octopus, hunting in a lagoon. Barathieu waited until spring tides when there was just 30cm of water on the flats and plenty of light in the shallows. (Photo by Gabriel Barathieu/UPY2017)

Indonesian students go to school via a makeshift suspension bridge in Ngemplak, Boyolali regency, Indonesia on November 15, 2017. The lack of access to roads makes students every day to cross the dangerous waterways to go to school. (Photo by Arief Setiadi/Pacific Press/Barcroft Images)