All of the Earth's ocean, from the equator to the poles, is a single-engine powered by sunlight – a blue machine. In a book that will recalibrate our view of this defining feature of our planet, physicist Helen Czerski dives deep to illuminate the murky depths of the ocean engine, examining the messengers, passengers and voyagers that live in it, travel over it, and survive because of it. From the ancient Polynesians who navigated the Pacific by reading the waves to permanent residents of the deep such as the Greenland shark that can live for hundreds of years, she explains the vast currents, invisible ocean walls and underwater waterfalls that all have their place in the ocean's complex, interlinked system. Timely, elegant and passionately argued, The Blue Machine is one of the biggest stories ever told. The understanding it offers is crucial to our future. Drawing on years of experience at the forefront of marine science, Helen Czerski captures the magnitude and subtlety of this complex force, showing us the thrilling extent to which we are at the mercy of this great engine.