OpenCPN is a free software (GPLv2) project to create a concise chart plotter and navigation software, for use underway or as a planning tool.
Cost / License
- Free
- Open Source
Platforms
- Mac
- Windows
- Linux

OpenSeaMap is described as ''s goal is to add nautical and tourism information a sailor could be interested in to OSM (OpenStreetMap) and to present it in a pleasing way' and is a Map service in the travel & location category. There are 2 alternatives to OpenSeaMap, not only websites but also apps for Mac, Windows, Linux and Self-Hosted. The best OpenSeaMap alternative is OpenCPN, which is both free and Open Source.
OpenCPN is a free software (GPLv2) project to create a concise chart plotter and navigation software, for use underway or as a planning tool.

OpenNauticalChart offers free seacharts for everybody. This charts are usable (offline) with several ship-plotters and Navigation-equipement on board.
