Discover the science, cultural history, and environmental importance of our planet's oceans. The second edition of this award-winning encyclopedia has been updated throughout and includes more than 20 additional entries and highlights timely concerns, including overfishing and microplastics, while also providing expanded coverage of the role oceans play in modern society, from cruise ships to the America's Cup competition. Part I of the book features a collection of 10 thematic essays, covering the five oceans of the world and broad areas of study such as the shipping industry and the changing nature of ocean boundaries. Part II includes more than 115 encyclopedia entries exploring topics ranging from the Bermuda Triangle to maritime law, from tsunamis to ocean acidification. Sidebars throughout offer fascinating facts that complement the main text. The oceans of the world are the lifeblood of our planet. They act as a climate regulator, absorbing heat and influencing weather patterns. The oceans teem with a vast and mostly unexplored diversity of life, providing us with food and medicine. Historically, oceans have been the highways of exploration and trade, connecting continents and fostering cultural exchange. From ancient Polynesian voyagers to modern shipping lanes, societies have relied on the oceans for transportation and resources. Yet, despite their vastness and importance, the world's oceans face numerous threats, including the effects of climate change, pollution, and exploitation of their bounty.