Oh nice, duden itself isn’t consistent with it’s content. Searching “Schiffahrt” gets me the result that the triple f is the old way of writing it: https://www.duden.de/rechtschreibung/Schiffahrt
But I don’t understand your last sentence. If both are correct than both are the right way. It’s just like “größer wie xy” is correct for a couple of years. Maybe it doesn’t sound nice, but it’s correct.
Do you mean until 1996? Looked it up on Duden.de and there it’s only “Schiffahrt” with the mention you wrote it “Schifffahrt” in the past.
No, since. In 1996 it went from being spelled with with double-f to triple-f. Since 2004 you can also write “Schiff-Fahrt”.
But triple-f is the correct spelling to this day.
https://www.duden.de/rechtschreibung/Schifffahrt
Oh nice, duden itself isn’t consistent with it’s content. Searching “Schiffahrt” gets me the result that the triple f is the old way of writing it: https://www.duden.de/rechtschreibung/Schiffahrt
But I don’t understand your last sentence. If both are correct than both are the right way. It’s just like “größer wie xy” is correct for a couple of years. Maybe it doesn’t sound nice, but it’s correct.