This book aims to provide a comprehensive overview of the subject, highlighting the significant advancements, challenges, and research developments in this rapidly evolving field. Throughout this book, a balanced blend of fundamental principles, state-of-the-art research, and practical applications are presented. It explores the challenges of designing and analyzing offshore foundations, pipelines, subsea tunnels, and other marine structures. The book also addresses the geotechnical aspects of dynamic loading, soil liquefaction, soil-structure interaction, and the assessment and mitigation of geohazards such as submarine landslides. This book will serve as a valuable reference, inspiring the next generation of marine geotechnical engineers and fostering further advancements in the field. As the demand for offshore resources and infrastructure continues to grow, the importance of understanding the geotechnical aspects of the marine environment becomes increasingly crucial. This book will contribute to the knowledge base and facilitate the development of innovative solutions to the challenges posed by the dynamic and demanding nature of the subsea environment.