Army Techniques Publication ATP 4-15 Army Watercraft Operations is the Army's doctrinal manual for Army watercraft operations. Its purpose is to provide authoritative doctrine on watercraft operations that support unified land operations. This publication applies to the range of military operations and supports Army Doctrine Publication (ADP) 3-0, Unified Land Operations, ADP 4-0, Sustainment and Field Manual (FM) 4-01, Army Transportation Operations. The intent of this FM is to support strategic and operational reach, and enable endurance. This ATP also establishes how watercraft operations are integrated and synchronized into the overall operations process - plan, prepare, execute, and assess. Transportation is identified as a sub-element of logistics in the Sustainment Warfighting Function. Army watercraft plays an integral part in support of the reception, staging and onward movement of forces. Watercraft support operation of strategic ports and provide the additional capability of moving forces forward via inland waterways. Watercraft are essential in establishing and supporting sea basing operations. The TBX provides mission command of watercraft in a combatant commander's area of operation. Army terminal battalions provide control of watercraft supporting terminal and sea basing operations. Army watercraft may support amphibious and riverine operations. Watercraft support the combatant commander in conducting unified land operations by providing the ability to move land forces to the desired location via the littorals, inland waterways and rivers. This capability extends operational reach and supports freedom of action. Army watercraft are the key enablers to achieving decisive action in unified land operations in operating environments requiring operations in the littorals. This publication describes watercraft transportation doctrine and its capabilities to support deployment and movement of expeditionary forces. It will relate how transportation supports unified land operations, sustainment and the distribution of equipment and materiel to Army and joint forces operating across the full range of military operations. ATP 4-15 contains seven chapters and two appendices. Chapter 1, Army Watercraft Fundamentals, covers the principles of watercraft operations, categories of watercraft, watercraft missions, maritime training, maritime qualifications and various duty positions of Soldier-Mariners. Chapter 2, Watercraft Capabilities and Supporting Organizations, describes the capability of Army watercraft and the organizations that support watercraft operations. This chapter also discusses mission command and the roles and responsibilities of organizations executing mission command. Chapter 3, Planning Watercraft Operations, discusses the planning requirements and considerations required for executing watercraft operations. It describes operational planning factors and security considerations for successful watercraft operations. Chapter 4, Executing Army Watercraft Operations, describes how watercraft support providing endurance to unified land operations. This chapter has four sections detailing watercraft, terminal, amphibious and riverine operations. Chapter 5, Vessel Security and Protection, describes the various threats to watercraft and methods for responding to each type of threat. Chapter 6, Watercraft Maintenance, describes types of watercraft maintenance, the organizations responsible for performing maintenance and requirements for maintenance reporting. Chapter 7, Watercraft Accident Reporting and Investigation, describes reporting procedures for watercraft accidents and responsibilities of the investigating officer. Appendix A lists and describes the various shipboard force protection levels and measures required to protect the vessel at each level. Appendix B lists the crew requirements for each vessel by platform.