Includes hydrographic survey information, NOS hydrographic survey index and index to adjoining sheets.
"NOS NN 4-2 (OCS)."
Mode of access: Internet from the NGDC NOAA web site. Address as of 3/6/08: http://www.ngdc.noaa.gov/mgg/bathymetry/maps/finals/NN%5F4-2/NN%5F4-2.pdf; current access via PURL.