This textbook is an introduction to oceanography for both science majors and non-science students (with the omission of some chapters). The text provides students with a basic understanding of the scientific questions, complexities, and uncertainties that are involved in ocean use, the role and importance of oceans in nurturing and sustaining life on the planet, and protection decisions in which they will participate as citizens. Critical concepts are drawn out and highlighted, first in an abbreviated format, then a more detailed explanation. The text includes a chapter on instrumentation and two chapters on plate tectonics. Critical thinking questions are found in every chapter.