David Hall’s photographs of scenery and creatures off the coast of Canada in the Pacific Northwest portray serenity under the water, which belie the extreme challenges he faces to get his images. For each shoot, Hall wears a dry suit, a neoprene body suit that covers all of his body but his head and traps air inside to keep him warm. Water temperature in Canada’s British Columbia typically ranges between 45 and 50 degrees Fahrenheit. Photo: Moon jellyfish and cross jellies. (Photo by David Hall)

People gather as a crowd of sea lions lay on floating docks at Pier 39 in San Francisco, California May 4, 2015. Hundreds of sea lions began hauling out on the docks following the Loma Prieta earthquake of 1989, and face no natural predators at the pier. (Photo by Robert Galbraith/Reuters)

The Sculpture Bank (2017) by Chinese artist Mu Boyan is exhibited along the Bondi to Tamarama Coastal walk as part of the Sculpture by the Sea exhibition in Sydney, Australia, October 18, 2018. (Photo by Charlotte Curd/The Guardian)

MS Allure of the Seas is an Oasis-class cruise ship owned and operated by Royal Caribbean International. The Oasis class are the largest passenger ships ever constructed, and Allure is 50 millimetres (2.0 in) longer than her sister ship Oasis of the Seas, though both were built to the same specifications. Designed under the name “Project Genesis”, she was ordered from Aker Finnyards in February 2006 and her construction began at the Perno shipyard, Turku, Finland, in February 2008. She was named in May 2008 after a contest was held to name her and her sister. The keel of Allure of the Seas was laid on 2 December 2008, shortly after the shipyard had been acquired by STX Europe.

A rescued malnourished sea lion is manually fed a fish at Sea World in San Diego, California March 17, 2015. Animal rescue centers in California are being inundated with stranded, starving sea lion pups, raising the possibility that the facilities could soon be overwhelmed, the federal agency coordinating the rescue said. (Photo by Mario Anzuoni/Reuters)

Faithful carry a boat out to sea, filled with offerings to Yemanja, the African sea goddess, during a ceremony honoring the deity in Montevideo, Uruguay, Saturday, February 2, 2013. Thousands of worshippers come to the beach in Montevideo on her feast day, February 2, bearing candles, flowers, perfumes and fruit to show their gratitude for her blessings bestowed upon them. The belief in the goddess sprouts from Umbanda, a blend of religions that include African, Catholicism and Spiritism. (Photo by Matilde Campodonico/AP Photo)

Palestinians and Israelis enjoy the Mediterranean sea during the first day of the Eid al-Fitr holiday in Tel Aviv, Israel, Thursday, August 8, 2013. The three-day Eid al-Fitr holiday marks the end of the holy fasting month of Ramadan. One of the most important holidays in the Muslim world, Eid al-Fitr, is marked with prayers, family reunions and other festivities. (Photo by Oded Balilty/AP Photo)