> Any free open source marine chart mapping programs? Dunno how far into the seas OSM data goes, but OsmAnd has an entire mode for boat navigation—I gawked at

> Any free open source marine chart mapping programs? Dunno how far into the seas OSM data goes, but OsmAnd has an entire mode for boat navigation—I gawked at it for an hour upon the discovery, looking at lighthouse locations and boat routes on the river and nearby seawater of my city. The app also has some kind of functionality for horse riders, though either the data is slim in these parts, or I don't know what to look for.