Charts and reference docs for the following areas can be downloaded here
Releases
2023 - added Crete (E, NE, NW), Med (Navionics high level)
2022 - (Australia, SE Asia, Indian Ocean, Red Sea, Med)
Instructions
Download and install OpenCPN, you will need a reasonable windows/mac that supports OpenGL (accelerated graphics) otherwise you may need to go legacy KAP charts.
Create a charts folder on your machine (in your documents folder for example). In there create a world folder for the world charts and region/country folders for the mbtiles.
Download and unzip the CM93 charts into the charts/world folder (these are the C-MAP world charts, base layer)
Create your country charts folders if not already done.
Download the mbtiles charts I have shared here and put them into that folder (you only need to download the ones you need)
Go back into OpenCPN settings, charts and add the country chart folders to opencpn.
OpenCPN should scan the additional charts
When you add/remove charts just go back to the charts tab in settings and tell OpenCPN to rescan/update charts