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)

Young Slovaks dressed in traditional costumes throw a bucket of water at a girl as part of Easter celebrations in the village of Trencianska Tepla, Slovakia, April 9, 2012. Slovakia's men splash women with water to symbolize youth, strength and beauty for the upcoming spring season. (Photo by Samuel Kubani/AFP)

A General Atomics MQ-9 Reaper stands on the runway during “Black Dart”, a live-fly, live fire demonstration of 55 unmanned aerial vehicles, or drones, at Naval Base Ventura County Sea Range, Point Mugu, near Oxnard, California July 31, 2015. (Photo by Patrick T. Fallon/Reuters)

A trapped car is pushed along a flooded street after typhoon Soudelor hit Fuzhou, Fujian province, China, August 9, 2015. The typhoon battered China's east coast on Sunday, killing eight people and forcing authorities to cancel hundreds of flights and evacuate more than 163,000 people. (Photo by Reuters/Stringer)

A Vietnamese woman collects dried incense sticks at a courtyard in Quang Phu Cau village on the outskirts of Hanoi on January 9, 2020 ahead of the upcoming Lunar New Year celebrations, referred to in Vietnam as Tet. (Photo by Manan Vatsyayana/AFP Photo)

Beesan al-Jubeh, (L), Palestinian under-10 national karate champion, trains with her father Sami (R) and other family members, all wearing face masks and gloves due to the COVID-19 coronavirus pandemic, outside their house in the city of Hebron in the Occupied West Bank on April 9, 2020. (Photo by Hazem Bader/AFP Photo)

4-year-old Tasmina adjusts her protective face mask as she waits with her family for a train at a railway station, as the outbreak of the coronavirus disease (COVID-19) continues, in Karachi, Pakistan on June 9, 2020. (Photo by Akhtar Soomro/Reuters)

Switzerland's Lea Sprunger in action during the 300m hurdles race during the Weltklasse Zurich Inspiration Games, a virtual international athletics meeting with 30 athletes in eight disciplines at seven venues worldwide, in the Letzigrund stadium in Zurich, Switzerland, Thursday, July 9, 2020. (Photo by Arnd Wiegmann/Reuters)