Notice of Availability of the Atlantic Fleet Training and Testing Final Supplemental Environmental Impact Statement/Overseas Environmental Impact Statement The Navy, Marine Corps, and Coast Guard, in cooperation with the National Marine Fisheries Service (NMFS), have prepared a Final Supplemental Environmental Impact Statement/Overseas Environmental Impact Statement (EIS/ OEIS) (ID# SEIS-007-17-USN-1723491961) that analyzes the potential environmental impacts from training and testing activities in 2025 and beyond conducted within the Navy’s Atlantic Fleet Training and Testing (AFTT) Study Area. This supplemental analysis updates the Navy’s 2018 Final EIS/OEIS with the best available science, changes to the regulatory environment, and refinements to the Study Area and Proposed Action. Proposed Action: The Navy, Marine Corps, and Coast Guard’s Proposed Action is to conduct military readiness training and testing activities including activities with active sonar and explosives in the AFTT Study Area, which includes the western Atlantic Ocean along the east coast of North America, the Gulf of America, and portions of the Caribbean Sea. The Study Area also includes Navy and Coast Guard pierside locations and port transit channels, bays, harbors, inshore waterways, and civilian ports where military readiness activities occur as well as vessel and aircraft transit routes over water between homeports and operating areas. The purpose of the Proposed Action is to ensure the Navy, Marine Corps, and Coast Guard are able to organize, train, and equip service members and personnel to meet their respective national defense missions in accordance with their Congressionally mandated requirements. These missions are achieved in part by conducting military readiness activities within the Study Area in accordance with established Department of the Navy military readiness requirements. The Proposed Action is needed to prepare the Navy, Marine Corps, and Coast Guard Forces to respond to world events, including large-scale conflict response, maritime security, and humanitarian assistance and disaster relief. Public Involvement: The completion of the Final Supplemental EIS/OEIS follows several years of research, analysis, and public involvement. Public input on the scope of the environmental analysis was obtained during the public scoping period November to December 2023. Following the public release of the Draft Supplemental EIS/OEIS, public input was obtained from September to November 2024. The Final Supplemental EIS/OEIS includes responses to the public comments received during the Draft Supplemental EIS/OEIS public comment period. The Final Supplemental EIS/OEIS will be available on the Navy's website beginning August 15, 2025 at www.nepa.navy.mil/aftteis. For more information visit the project website at www.nepa.navy.mil/ aftteis or contact: Naval Facilities Engineering Systems Command Atlantic, Attention: Code EV22SG (AFTT EIS Project Managers) 6506 Hampton Blvd., Norfolk, VA 23508-1278