This book was originally written for my Principles of Oceanography course at Roger Williams University, a lower-level introductory course required for marine biology and environmental science majors. By design, this course does not go into great detail about marine biological topics, as our students will cover those topics in their other courses. For that reason, this book does not currently include sections on marine ecology, marine communities, or the diversity of marine life that are often found in other introductory texts. However, this book remains a work in progress, and it is hoped that over time, those sections may be added. I invite instructors who utilize this text to send suggestions, edits, updates, or sections you would like to see added to firstname.lastname@example.org. I especially encourage instructors who are willing to author additional sections in their areas of expertise to submit them for inclusion in future updates to this text.