The ferries across the Kiel Canal run around the clock as needed. You'll definitely come over, no matter when you come. And it's free. There is nothing to complain about. ;)
The original of an old, disused ferry is exhibited on the southern side of the NOK in Fischerhütte and you can pause under old linden trees with a direct view …
Built in the years 1984-1986, after the old arch bridge became dilapidated and too shallow, this new railway and car bridge was built near the old site.