http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
6th ed., Nov. 9, 1985 (correct through NM 45/85).
compiled from various sources to 1957 ; prepared and published by the Defense Mapping Agency Hydrographic/Topographic Center.
Relief shown by shading and spot heights.
"Soundings in fathoms and feet, depth contours in fathoms."
Inset: 1985 magnetic variation curves in purple.
"Copyright restrictions of the country of origin continue to exist."
Includes compilation data and tide table.