Water Column Sonar Data Collection

NOAA collects and uses active acoustic (or sonar) data for a variety of mapping requirements. As the national archive for multibeam bathymetric data, NGDC manages over 15 million nautical miles of ship trackline data from sources worldwide. In 2011, NGDC, in partnership with NOAA’s National Marine Fisheries Service (NMFS), initiated a new archive for high resolution data collected with sonars capable of mapping the water column.

Water column sonar data are collected on NOAA fishery survey vessels and academic and international fleets, and are used to assess the physical and biological characteristics of the ocean. Primary uses include 3-D mapping of fish schools and other mid-water marine organisms, assessing biological abundance, species identification, and habitat characterization. These data are also useful for evaluating underwater gas seeps, remotely monitoring undersea oil spills, and bathymetry.

NGDC is working with scientists at NMFS and the Joint Hydrographic Center to ensure the long-term preservation and world-wide dissemination of these data.

Maritime Limits and Boundaries of the United States

NOAA is responsible for depicting on its nautical charts the limits of the 12 nautical mile Territorial Sea, 24 nautical mile Contiguous Zone, and 200 nautical mile Exclusive Economic Zone (EEZ). The outer limit of each of these zones is measured from the U.S. normal baseline, which coincides with the low water line depicted on NOAA charts and includes closing lines across the entrances of legal bays and rivers, consistent with international law.


MarineCadastre.gov is a joint Bureau of Ocean Energy Management (BOEM) and National Oceanic and Atmospheric Administration (NOAA) initiative that provides authoritative data to meet the needs of the offshore energy and marine planning communities. The website provides access to authoritative data from multiple agencies, including offshore boundaries and physical, biological, ocean use, and cultural information. Users can create, view, and print maps from this free, easy-to-use viewer, or can directly link to the web map services through their own GIS applications.