A new book published by the UK Natural History Museum showcases some of the most memorable underwater photographs taken over the last few decades in its annual wildlife photographer of the year competition. Here: Giant gathering by Tony Wu. “The first indication that something extraordinary was going on were the blows, huge numbers of them – the exhalations of huge numbers of whales. Entering the water, the photographer witnessed an extraordinary scene”. (Photo by Tony Wu/Unforgettable Underwater Photography/NHM)

A loved-up couple have captured the moments they shared a dip-kiss in different locations around the world. Rob, 34, and Joli Switzer, 33, from Maryland, embark on a minimum of four international holidays per year to ensure that they get their unique dip-kiss photograph. Here: Rob Switzer 34 proposed to Joli 33 whilst they were on holiday in Moscow, Russia. (Photo by Dipkiss Travels/Caters News Agency)

These brave models show no fear as they pose with bears, tigers and wolves in scenes straight from the pages of a fairy tale. The snaps show the models cuddling up to the deadly animals and even taking naps with the often unpredictable creatures. Here: “Marina with a bear”. Stepan, a 700-pound grizzly bear, was adopted by a Russian couple when he was just 3 months old. (Photo by Olga Barantseva/Caters News Agency)

This absolute hero came to the rescue when flash floods in a World Cup city left two women stranded in their submerged cars. Here: A woman is rescued from a car after a flash flood in Nizhny Novgorod, Russia on June 19, 2018. (Photo by Lucy Nicholson/Reuters)

Comic Con fans in costume arrive for the 1st day of the 2018 New York Comic-Con at the Jacob Javits Center on October 4, 2018. The four-day event which runs October 4-7 is the largest pop culture event on the East Coast. (Photo by Timothy A. Clary/AFP Photo)

Merfolk gather at MerMania 2017, the world's largest gathering of amateur and professional mermaids and mermen in North Carloina, USA on January 21, 2017. (Photo by Brian Cahn/ZUMA Wire/Rex Features/Shutterstock)

Kourtney Roy makes eerie self-portraits in desolate yet dramatic locations – with wigs and wardrobe straight out of 1950s melodrama. In these shots, from her “Enter as Fiction – California” series, she plays characters caught in desolate, often abandoned settings. (Photo by Kourtney Roy/Galerie Catherine et André Hug/The Guardian)

Rwandan refugees cross the Rusumo border to Tanzania from Rwanda carrying their belongings, goats, mattresses and cows, May 30, 1994. The bloodshed that claimed 800,000 Tutsi and moderate Hutu lives began 25 years ago on April 7, 1994, when a plane carrying Rwandan President Juvenal Habyarimana, Burundi President Cyprien Ntaryamira and a French air crew was shot down. (Photo by Jeremiah Kamau/Reuters)