Book excerpt: Where did the oceans come from? Can you take a submarine to the bottom of the sea? What exactly is a coral reef? Learn about ocean creatures big and small, and how humans explore the underwater world in this incredible illustrated book on the depths of the sea. Join your helpful guide, Professor Astro Cat, as he takes a dive from the seashore all the way to the ocean floor. From whales to deep-sea vents, there's so much to discover on this Deep-Sea Voyage.