THE free and open source chart plotter: opencpn.org
- numerous chart formats supported
- individual user interface
- AIS collision alert
- integration of weather and current gribs
- NMEA0183 interface (SignalK support under development)
- tactics plugIn
- …
Official vector charts (iENCs) are available free of charge for inland waterways in Europe and the USA. Offshore charts (oeENCs) made available via o-charts.org at low cost.