A complete global CM93 v2 dataset can be quite large. For users who only need specific regions, it is possible to work with partial datasets. OpenCPN explicitly supports partial CM93 datasets covering only one or a few geographical regions, which can significantly reduce storage and processing requirements.
You cannot just "buy" CM93 v2 from a store anymore. Distribution is almost entirely via peer-to-peer and sailing forums (e.g., CruisersForum, Panbo, or OpenCPN user groups).
The Complete Guide to CM93 v2 Charts: Download, Installation, and OpenCPN Configuration
: A complete worldwide dataset features up to 144 subdirectories mathematically named from 00300000 to 04501020 . cm93 v2 charts download install
If you tell me your OS (Windows/macOS/Linux) and whether you're using OpenCPN, I can provide exact folder paths and step-by-step commands.
OpenCPN recognizes CM93 charts if placed in its chart directories and index updated.
OpenCPN shows only a black background with basic outlines, no detailed charts. A complete global CM93 v2 dataset can be quite large
| Source | Quality | Update Frequency | Cost | Use Case | | :--- | :--- | :--- | :--- | :--- | | | Fair/Outdated | Never (2013) | Free (community) | Ocean passage planning, backup | | OE SENC (o-charts) | Very High | Monthly | $35–150/year | Official vector charts (EU, US) | | Satellite imagery (SAS.Planet) | High | 2020–2025 | Free | Anchoring, reef spotting | | RNC Raster (NOAA) | Good | Weekly | Free (USA only) | US coastal navigation |
CM93 v2 charts remain a popular resource among the cruising community, offering worldwide vector coverage that works seamlessly with OpenCPN and other navigation software. While the installation process is straightforward—simply adding the chart directory and letting OpenCPN scan—responsible navigators must remain aware of the serious safety implications of using outdated, unmaintained chart data.
in unfamiliar, hazardous, or changing waters. The charts may be years out of date and lack critical updates. You cannot just "buy" CM93 v2 from a store anymore
The are a widely recognized worldwide database of vector nautical charts originally developed by C-Map. While significantly aged, they remain a popular resource for sailors using open-source navigation software like OpenCPN because they are unencrypted and cover most of the world's oceans and coastal areas. The Legacy of CM93 v2
Zoom in on various regions of the world map. Initially, you may see only outline boxes representing available chart coverage. As you zoom in, OpenCPN will automatically load the appropriate scale-level chart. If you see green squares in place of charts, you have successfully added the directory—zoom in further on a green square to load the actual chart.
Some users have reported success by manually downloading ENC charts from NOAA's website and converting them to work within CM93-compatible systems. In one documented case, a user successfully installed U.S. East Coast charts by manually downloading from NOAA and then deleting certain files ( readme.txt , Catalog.031 , and USERAGREEMENT.TXT ). While this method works, it is labor-intensive and requires manual updates. Others have noted data volume issues causing crashes—often caused by a single corrupted chart file rather than the size of the dataset. The solution is to isolate and remove the problematic file.