A Romanian female soldier adjusts her helmet before taking part in weapons training with US Marines female counterparts at the Capu Midia Surface to Air Firing Range, on the Black Sea coast in Romania, Monday, March 20, 2017. About 1,200 US and Romanian troops take part in the Spring Storm 17 exercise, meant to simulate defense of the Romanian Black Sea coastline and urban areas. (Photo by Vadim Ghirda/AP Photo)

The Bajau people of Malaysia live their lives completely at sea, living in wooden huts and spending their days fishing. Sailing over crystal clear waters, the Bajau people of Malaysia live their lives almost entirely at sea. Photographer Ng Choo Kia joined the Bajau people on their pirogues, which are long narrow canoes made from single tree trunks, and documented their daily life in a series of pictures. (Photo by Ng Choo Kia/Hotspot Media/SIPA Press)

Crew in Britain's first ever full-size reconstructed sea-going Bronze Age boat, paddle out to sea near to the National Maritime Museum as it makes its maiden voyage on March 6, 2013 in Falmouth, England. (Photo by Matt Cardy)

This November 8, 2019, photo provided by John Guillote shows a view from the main lab of the Sikuliaq in the Chukchi Sea. University of Washington scientists onboard the research vessel are studying the changes and how less sea ice will affect coastlines, which already are vulnerable to erosion because increased waves delivered by storms. More erosion would increase the chance of winter flooding in villages and danger to hunters in small boats. (Photo by John Guillote via AP Photo)

A Puffin jumps into its burrow with a mouthful of sea eels to feed its chick on Skomer Island, Pembrokeshire in Wales, Britain June 21, 2016. (Photo by Rebecca Naden/Reuters)

A man lies in the sea grass at a beach on July 18, 2016 in Qingdao, Shandong Province of China. The enteromorpha prolifera spread on the beaches in Qingdao and were under clearing. (Photo by VCG/VCG via Getty Images)

A cat and a seagull feeding on a street in Heybeliada, the second largest of the Prince Islands in the Sea of Marmara, near Istanbul, Turkey on February 01, 2017. (Photo by Sebnem Coskun/Anadolu Agency/Getty Images)

These are the stomach-churning pictures of the swing at the end of the world – a rickety wooden swing hanging over a precipice 2,660 metres above sea level – and not a seatbelt in sight. (Photo by Caters News)