The Y-40 Deep Joy is the worlds deepest pool. Y-40 is projected by Architect Emanuele Boaretto and supported by the “Boaretto Group Hotel and Resort”. The name Y-40 is inspired by mathematical symbols. “Y” is the ordinate axis of the Cartesian system and “–40” means the world's record depth or our pool- that is 40 meters underground. (Photo by Courtesy Y40 Deep Joy)

Two giant puppets, a deep sea diver and his niece, roam through the streets of Liverpool, northern England, and April 20–23 looking for each other during the Sea Odyssey festival. The free event, organized by the French company Royal de Luxe is one of a series of events marking the 100th anniversary of the sinking of The Titanic. The liner, registered in Liverpool, sank on its maiden voyage to New York on April 15, 1912.

Photo: A giant deep sea diver emerges from the Albert Dock to begin a journey through the streets of Liverpool during the Titanic Sea Odyssey on April 20 in Liverpool, England. (Photo by Christopher Furlong)

An octopus is filmed by the National Oceanic and Atmospheric Administration ship Okeanos Explorer and its robotic sub. (Photo by National Oceanic and Atmospheric Administration)

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