It appears you may have taken the photo from a boat. Maybe a slight movement due to the water or someone moving in the boat resulted in some camera movement relative to the view. Of course, you may have been on a bridge or quay, in which case my hypothesis is invalid.
But it could still be camera movement especially if the whole image is slightly out of focus. (I can't tell from the image you posted, either).
If the lens was out of focus I would have expected that at some identifiable point in the scene some of it would have been in focus unless you took it wide open. That's unlikely with full sun, a Summicron and 400 ISO film.
Rolleiflex (3): E2 Planar 2.8, WA & Tele
Nikkormat FTn (2)