Navigational Charts added to NARA’s Format Guidance Bulletin

This post is written by Sharmila Bhatia and Michael Horsley.

We have added Navigational Charts to Appendix A: Table of File Formats of NARA Bulletin 2014-04, Format Guidance for the Transfer of Permanent Records. Records in this format can now be transferred as permanent records to the National Archives. 

Navigational charts are tools used to provide safe navigation for all classes of vessels. Official charts are issued by a government, hydrographic office, or other government institution, and comply with standards developed by the International Hydrographic Organization (IHO). These charts show detailed configurations of the seabed, characteristics of the coast, routes, and aids to navigation. In addition to navigational purposes, the information is used by construction engineers, dredging contractors, oceanographers, defense departments, and coastal zone managers. 

There are two types of electronic navigational charts—raster charts and vector charts: 

  • Electronic Navigational Charts (ENC) are vector data sets of all the objects (points, lines, and areas) represented on a chart in a digital database.
  • Raster Navigational Charts (RNC) are digitized raster copies of official paper charts.

ENC charts are designed to be used with an Electronic Chart Display and Information System (ECDIS).  RNC charts are high-resolution scans with color separate overlays that contain geo-referencing data. 

If you have questions about this, please leave a comment or email