The problem with Navionics is all charts are stored in the internal storage of the tablet. It is not possible to put the charts on extra sd-cards.
As I have C-map on Furuno Navnet and Maxsea , the Navionics are good on the tablet. Navionics gave information of the inlets of the US Eastcoast where C-map shows zero !
This year a catamaran hit a reef not shown on Navionics - always have several informations in these places.Don't miss the papercharts at the Exumas, Bahamas.
Wolfgang Weber SY Elise Amel 54#162