If the charts do not render immediately, you may need to enable the CM93 plugin:
If you see blank gray water, your directory path is wrong, or OpenCPN could not read the encryption.
Never rely solely on CM93 v2. Here is a tiered strategy for safe navigation: cm93 v2 charts download install
| Source | Quality | Update Frequency | Cost | Use Case | | :--- | :--- | :--- | :--- | :--- | | CM93 v2 | Fair/Outdated | Never (2013) | Free (community) | Ocean passage planning, backup | | OE SENC (o-charts) | Very High | Monthly | $35–150/year | Official vector charts (EU,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 |
These charts are old; the codebase is even older. Here’s how to make them run smoothly on a laptop or marine PC: If the charts do not render immediately, you
| Source | Format | Cost | Software | |--------|--------|------|----------| | Official ENCs | S-57 / S-63 | Free–low (e.g., NOAA, CHS, UKHO) | OpenCPN, qGIS, SeaClear | | C-MAP Reveal | Proprietary vector | Subscription | C-MAP apps, Lowrance, Simrad | | NV Charts | Raster + vector | Paid region | NV Atlas, TimeZero | | Navionics | SonarChart™ | Subscription | Navionics Boating |
For free legal global charts, use OpenCPN with the OE-SENC plugin (O-Charts) – official S-63 ENCs at ~€25–50 per region. Never rely solely on CM93 v2
Assuming you have found a valid source (often a .torrent file or a compressed RAR archive), follow these steps:
Here lies the crux of the matter. Hydrographic offices, private companies like C-MAP, and national maritime agencies invest millions in surveying, maintaining, and updating nautical charts. An outdated chart—even a centimeter of shifted coastline or a missing wreck—can lead to grounding, collision, or loss of life.
Using a static, decade-old chart set like CM93 v2 for primary navigation is hazardous. Sandbars shift, buoys are relocated, new wind farms appear. In many jurisdictions, using unlicensed, outdated charts can void insurance or even lead to legal liability after an incident.
The ethical sailor treats CM93 v2 as a planning and backup tool, not a primary source. The responsible workflow is: