Official Protraction Diagrams (OPD)

A standard OPD is 1 degree in latitude by 2 degrees in longitude (at lower latitudes: 0 - 48 degrees) as in the Gulf of Mexico.  At higher latitudes (48 - 75 degrees) such as Alaska and northern Washington, OPDs are 3 degrees wide.  OPD limits usually approximate the standard 1:250,000 scale U.S. Geological Survey topographic map series.  The OPDs are numbered using the United Nations International Map of the World Numbering System.  OPD names usually coincide with standard topographic sheet names when diagrams include land areas.  OPD sheet names relate to land features, or to hydrographic features contained within the limits of the diagram.  Shoreline planimetric detail is shown when it falls within the limits of a diagram.  Older OPDs were prepared on mylar with manual cartographic methods and then scanned into Adobe .pdf files.  Newer OPDs were prepared electronically and converted to Arc Info .gra files and Adobe .pdf files. 

The status of Eastern Gulf of Mexico OPDs remains as stated in the January 13, 2000, Federal Register notice (65 FR 2191).

Listed in the table below are OPDs available in two formats: