The book opens by explaining how different types of animals are able to breathe and survive underwater, and the different families to which they belong. Subsequent pages are dedicated to specific creatures, including sea turtles, whales, sharks, stingrays, and seahorses, and show varied life in specific habitats, such as a coral reef or deep sea bed. The Big Book of the Blue also explores the underwater world thematically, looking at animals in danger, learning how to spot creatures at the beach, and discovering how to do our part to save sea life.