With the recent release of the version 5 of the S63 plugin, and the use of the latest 3.3 beta version of OpenCPN ...S63 charts are now supported. A separate commercial entity http://www.o-charts.org/
, handles the plugin, that is not free and not open source.
Register, pay your fee, choose and pay your chart selection ... and off you go, with up to date charts. These are the same official charts that shipping worldwide uses daily. It is all explained on the o-charts site.