CM93 v2 charts are worldwide vector charts originally created by C-MAP. While newer formats like CM93 v3 exist, the version 2 format remains widely popular because it uses an open structure that is directly compatible with free navigation software like OpenCPN. Key Features
If the charts are installed correctly, you will see detailed vector data.
This distinction is crucial. CM93 v3 charts are fully compliant with the IHO S-57 Edition 3.0 standard and support automatic updates. Importantly, most open-source chart plotting software—including OpenCPN—does not support CM93 v3, which remains a proprietary format requiring specific license keys. For users of free and open-source navigation tools, CM93 v2 remains the more practical choice despite being discontinued and increasingly dated.
: Select the Charts tab, then Chart Files .
For sailors and marine navigators seeking a free charting solution, "CM93 v2" often appears in forums and discussions. These vector charts, while widely used and circulated within the boating community, come with significant caveats. This comprehensive article explains what CM93 v2 charts are, how to find and download them, and the step-by-step process for installation in chart-plotting software. Most importantly, we’ll discuss the critical safety and legal considerations every mariner should understand before relying on this data. cm93 v2 charts download install
: The database is organized into sub-directories named by scale, ranging from Z (global overviews) down to G (detailed harbour plans). Loading in OpenCPN :
If the database rebuild fails, move the chart folder to a shorter, simpler file path (e.g., C:\CM93\ ).
To follow this guide, you will need:
Navigate to and select the top-level folder of your CM93 v2 dataset (the folder containing the numeric subfolders). Click . Step 4: Rebuild the Database Within the Chart tab, ensure "Scan for Changes" is checked. CM93 v2 charts are worldwide vector charts originally
Q: What is the difference between CM93 V2 charts and other chart types? A: CM93 V2 charts are a type of electronic chart that provides detailed and accurate navigation data, whereas other chart types, such as raster charts, may not offer the same level of detail and accuracy.
: The dataset is organized into 144 subdirectories (e.g., 00300000 to 04501020 ), each covering a geographic area.
Now go download, install, and sail with confidence—but keep one hand on the paper chart.
If you are setting this up for an upcoming trip, let me know: This distinction is crucial
: Check the box for Depth Soundings to see spot depths.
If you want to work with only a specific geographical area, understanding the region code system allows you to select only the necessary subdirectories. The formula for decoding a region code is:
: Remember that CM93 v2 datasets generally date back to the mid-2010s or earlier. Newer wind farms, shifted sandbars, and updated buoyage systems will not appear. Always cross-reference your route with up-to-date satellite imagery, local cruising guides, and official government hydrographic notices to mariners.
The or behavior you are seeing (e.g., "chart directory empty", "crashing on build")