The document discusses the major bodies of water on Earth, including the four oceans (Pacific, Atlantic, Indian, Arctic) as well as the Southern Ocean. It notes that the Pacific Ocean is the largest and deepest. It also describes coral reefs, how they are formed by coral polyps' skeletons growing on top of old skeletons in warm, shallow seas. Finally, it outlines the different zones in the oceans from the sunlit zone near the surface down to the deepest sunless zone.