Though we think of Earth's five oceans as separate and distinct, they are actually a linked system of circulating water that is one single ocean --- the global ocean. This comprehensive and accessible overview explores the global ocean's enormous influence on the planet, as well as humans' often-detrimental influence on the ocean. But it also highlights some of the many ways people are working to restore and heal the global ocean --- from everyday actions to large institutional projects --- making the message of urgency as hopeful as it is accurate. Filled with fascinating information, stunning visuals and plenty of calls to action, readers will be inspired to discover what they can do to help heal Earth's most important feature and, ultimately, our planet.