The peccant part is - beside the presentation of the chart, paper or electronic, what is the chart based on.
If it is based on the AHO's, the British Admiralty, NOAA, or any other countries OFFICIAL (Aust. Hydrographic Office), paper (raster format) charts even if it is in electronic form, (ENC) is an official chart,
the scanned form of the paper charts, so stated on the chart and as such, safe and recommended for navigation.
Jeppesens, the world's largest chart company supplies the merchant ships world over with ENC's which are based not on a bunch of commercial mappers compilation of charts of doubtful origin but,
are the scanned paper charts presented in graphic or vector format
released by a Hydrographic Office of a country, recommended for navigation just presented in vector format.
The experience of the hydrographic offices is the sad truth, that the commercially produced charts or ENC's could be compiled with much less rigour by less responsible map makers who are driven by profitability not safety concerns.
Navionic is one of the large mappers who try to cash in on a recently exponentionally growing worldwide demand for charts.
They dilute the data of a paper chart and add gadgets, interesting things which is catching the customers with their coruscating appearance and add layers for customer interaction which is popular amongst users and with customer based additions dilute further the paper charts data which is buried deeper and deeper in commercial mediocrity.
All RNC's are based on paper charts while only some ENC's are based on them.
This madness is promoted and swallowed by many except staunch old farts like me, who would NOT under any circumstances navigate with one of those craps (maps)!
I got part of this info from the AHO's website. It is fascinating reading to clear up this subject.
www.hydro.gov.au/