| Notes: | A vector-based digital file containing marine features suitable for marine navigation. The file is based on the International Hydrographic Organization (IHO) S-57 standard. The file extension, ".000," for a base NOAA ENC cell is used for updating. The first update for a cell will be ".001" the next ".002" and so forth. The file extension .031 is used for catalog data (metadata) relating to the chart data. |
