The National Search and Rescue Supplement (NSS) supplements which manual?

The National Search and Rescue Supplement (NSS) is designed to enhance and provide additional guidelines to the International Aeronautical and Maritime Search and Rescue (IAMSAR) Manual, which serves as a comprehensive resource for coordinating search and rescue operations globally. The NSS specifically focuses on adapting the IAMSAR Manual's principles and procedures to meet the needs and complexities of search and rescue operations within the United States. This makes it the foundational document for SAR operations, ensuring effective collaboration among various agencies.

By aligning with the IAMSAR Manual, the NSS helps local, regional, and national SAR teams operate cohesively and efficiently, enabling them to respond more effectively to search and rescue missions. This connection underscores the importance of international standards while tailoring them to specific national requirements.

The other options, while important in their respective contexts, do not directly relate to the NSS's role in supplementing principles and procedures for SAR operations as outlined in the IAMSAR Manual.