Marine Safety Information Bulletins

National-level MSIBs: U.S. Coast Guard Marine Safety Information Bulletins issued by Headquarters or a national program office to communicate maritime safety, security, environmental, regulatory, or policy information that affects stakeholders across multiple regions or nationwide.
District/Sector MSIBs: Coast Guard MSIBs issued by a District or local Sector/Captain of the Port to communicate region- or port-specific maritime information, such as local safety zones, waterway restrictions, marine events, hazards, and enforcement guidance. District offices provide regional coordination; Sectors operate within defined local areas of responsibility