Book excerpt: This book reviews the field of physical oceanography, starting with its history and culminating in the past, present and future challenges of this scientific discipline. It introduces the different aspects of the science, and presents the observational and computational tools used by physical oceanographers. It discusses the day-to-day activities of the physical oceanographers located at universities, government laboratories and industry, and relates the physics of the ocean to such topical issues as climate change and ocean forecasting. The book also presents a review of the historical challenges for physical oceanography and an overview of some of the most important challenges facing physical oceanography today. Reading this book will prove useful to anyone wanting to better understand how the ocean fits into the complex system that makes up the global environment.