Comment by RunningDroid
10 hours ago
Rumor has it that routers have the same issue with highway areas so best practice is to add a "spine" to them
https://wiki.openstreetmap.org/wiki/Key:area:highway#Routers
https://wiki.openstreetmap.org/wiki/Proposal:Area_highway/ma...
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.