OpenCPN is a free software (GPLv2) project to create a concise chartplotter and navigation software for use as an underway or planning tool. OpenCPN is developed by a team of active sailors using real world conditions for program testing and refinement.
Worldwide standard S57 and encrypted S63 vector chart support. BSB v3 and earlier raster charts. CM93 vector charts with per cell offset corrections. Up-to-date ENCs for selected worldwide regions, distributed by o-charts.org
AIS input with full target-tracking and collision alerting. AIS support for SART with selectable MMSI for automatic MOB handling. AIS support for DSC and GPSGate buddies.
Route planning with tidal support. Built-in great-circle routing. Integrated weather routing through qtVim or separate plugin.
Plugins: Climatology, Weather Routing, WeatherFax, Google Earth, Voyage Data Recorder, AIS-radar, SAR, sQuiddio, Radar Overlay, Logbook, and many more.