That's the problem with some maps.
Look here to this layer Tracetrack Topo.. 
https://www.openstreetmap.org/#map=19/52.320085/4.827354&layers=PN

It's the choise of the mapdevelopper. :)

OSM is not a map... it's a database.
Anyway... te boat_rental is in this database and you will find the right spot.



