I've had the nautical navigation work fine when canoeing on rivers and streams where you're following linear features on the map. What it lacks is the ability to plot a sensible course across a polygon of open water.
The presence of such spines in open bodies of water just makes nautical routes come out particularly stupid, where the route presented calls for you to immediately go to that spine and travel along it, unnecessarily lengthening the route.
RunningDroid|3 days ago
https://wiki.openstreetmap.org/wiki/Key:area:highway#Routers
https://wiki.openstreetmap.org/wiki/Proposal:Area_highway/ma...
wtallis|3 days ago