Survey Data

NOAA nautical chart overlaid with color-coded bathymetric contours and hydrographic survey depths.

Hydrographic surveys are used to compile the official nautical charts for the United States and its territories. Although the primary use for these surveys is chart compilation, they are also available to the general public via NOAA’s National Geophysical Data Center (NDGC). Additional archived survey records are available from the National Archives and Records Administration and Library of Congress

Note: NOAA maintains a separate archive of historical maps and charts, the final products produced from Coast Survey’s hydrographic surveys and other original sources. More information is available in the Historical Maps and Charts Collection.

Graphic of a hydrographic survey smooth sheet showing depths through a river and hydrographic title block.

Digital Data for Download

NOAA’s National Geophysical Data Center (NGDC) is the data archive and distribution center for Office of Coast Survey (OCS) digital hydrographic data. NGDC maintains the National Ocean Service Hydrographic Data Base (NOSHDB) providing survey coverage of the coastal waters and Exclusive Economic Zone (EEZ) of the United States and its territories.

Survey data and products available from NGDC vary depending on the age of survey, but generally include Descriptive Reports (DRs), smooth sheet images, survey data images, and gridded digital bathymetric data for use in Geographic Information Systems (GIS). Most OCS surveys have at least a copy of the DR (a narrative document describing the conditions under which the work was performed and factors affecting the adequacy and accuracy of the results) and a scanned raster image of the smooth sheet (a final, neatly drafted, accurate plot of a hydrographic survey). The NOSHDB also contains bathymetric data digitized from smooth sheets of hydrographic surveys completed between 1837 and the mid-1970's, and higher resolution digital data for surveys acquired and processed electronically since the early 1970's. Some survey records may also include raster images of side scan or multibeam sonar backscatter mosaics.

Metadata for all surveys is available in Federal Geographic Data Committee (FGDC) format, as well as a more intuitive format developed by OCS called the “Survey Rap Sheet”. OCS data products available from NGDC may be searched, viewed, and downloaded using the NOS Hydrographic Survey Data Viewer.

Archived Paper Records

Historic paper records of NOS Hydrographic Surveys are retained by the National Archives and Records Administration (NARA) and Library of Congress. Points of contact for these facilities are listed below.

National Archives and Records Administration
NARA is the permanent archive for original hard copy hydrographic survey records, such as descriptive reports and smooth sheets. Record location information for many surveys is available in the Rap Sheet metadata view through NGDC as described above.
Contact Information:
National Archives and Records Administration
8601 Adelphi Road
College Park, Maryland 20740
carto@nara.gov

Library of Congress
The Library of Congress holds a limited number of hydrographic survey field records. These records are listed in the Library’s catalog.
Contact Information:
Library of Congress Geography and Map Division
101 Independence Avenue, S.E.
Washington D.C.20540
(202) 797-6277

Additionally, some ancillary and supplemental hydrographic survey records such as paper fathometer traces and sounding logs are held on a non-permanent basis by NARA’s Federal Records Center. Access to these data may be requested under the terms of the Freedom Of Information Act (FOIA). Interested parties may initiate a FOIA request through the OCS Inquiry System.

Descriptive report cover for hydrographic survey.