The OpenCPN documentation is very clear on this point:
So, why should traders consider using CM93 V2 charts? Here are just a few benefits: cm93 v2 charts download
Because C-MAP no longer sells or supports CM93 v2 (it was replaced by and other cloud-based services), the only way to obtain it is through unofficial channels : The OpenCPN documentation is very clear on this
: Many "free download" links on forums or file-sharing sites are deceptive and may attempt to install malicious software or browser hijackers. Legal & Official Status For official, safe navigation in the USA: NOAA
For : OpenSeaMap. For official, safe navigation in the USA: NOAA ENC charts (via Chart Downloader). For official, safe navigation globally: o-charts (paid) or S63 charts.
Open-source navigation engines strictly read . Later iterations, like C-Map Version 3 (v3), utilize a preprocessed proprietary System Electronic Navigational Chart (SENC) container. Modern marine software cannot decode v3 charts. Navigators must confirm that their directory structure shows the individual numeric folders and the .EXD version file, or the navigation software will fail to recognize the chart group. Chart Download and Sourcing Alternatives