South American sea lion. Valencia, February 8, 2012. (Photo by Ger Art; Source: Flickr)

A couple watch the sunrise in front of the Mediterranean Sea in Barcelona, Spain, Sunday, January 24, 2021. (Photo by Emilio Morenatti/AP Photo)

A fisherman waits to catch fish as he sits atop a stilt in the sea in Koggala, Sri Lanka on July 4, 2019. (Photo by Dinuka Liyanawatte/Reuters)

Shooting star by Tony Wu, US/Japan. Winner, underwater. The electrifying reproductive dance of a giant sea star. As the surrounding water filled with sperm and eggs from spawning sea stars, Wu faced several challenges. Stuck in a small, enclosed bay with only a macro lens for photographing small subjects, he backed up to squeeze the undulating sea star into his field of view. The dancing posture of spawning sea stars rising and swaying may help release eggs and sperm, or may help sweep the eggs and sperm into the currents where they fertilise together in the water. Kinko Bay, Japan. (Photo by Tony Wu/Wildlife Photographer of the Year)

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)

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)

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)