This book presents the state-of-the-art report on the long-term exposure practice of structural concretes in marine environments, prepared by the RILEM Technical Committee 289-DCM. The report is composed of an introductory chapter, five technical chapters, and a chapter of conclusions and perspectives. The technical contents cover the mechanisms and factors for concrete exposed in marine environments, the information and presentation of exposure data, the interpretation and exploitation of exposure data, the technical guideline for practice, and the support for life-cycle management by exposure practice. The book benefits the academics and practitioners in long-term exposure practice of concrete in marine environments.