Do NOAA ENC®s have edition numbers or print dates like paper charts?
Answer – In short, yes they do. Every NOAA ENC® starts with a file header that has various information, metadata, about that particular NOAA ENC®. The header has a number of “subfields,” each of which has information about a particular aspect of the NOAA ENC®. One subfield is the edition number, which is a sequential number that works just like the edition number on a paper chart. The first time an NOAA ENC® is issued, it is edition one (1), which is subsequently superseded by edition two (2) and so forth. There is also a subfield called issue date which is the first date that the NOAA ENC® may be used for navigation. Finally, the update application date subfield indicates the last date through which an update was available for use (Notices to Mariners in particular).