So, the investigation was not quite necessary, but successful :) Dear Gordon, yes, thank you very much!
It is very useful for me to know the date, as it makes possible to track service story and modifications,
or estimate the dates, wherever unknown. Especially, when it comes to my favourite "Hel" class.
For example, after accident on 17.02.1983, "Władysławowo" got visible dent in shell, below port side gangway.
Stay safe :)

Hi Marcin,
In answer to your question the picture was taken from the Vistafjord and she was due to be docked between 8.00 am and 5.00 pm on the 9th August 1982. I hope this information is of help to you.
Best Regards
Gordon

I was wondering, if it would be possible to guess any closer date, when this picture was taken.

For comparison, in this picture:
http://www.shipspotting.com/gallery/photo.php?lid=2404377
"Henryk Jendza" has identical rust/fresh paint pattern, but unfortunately, there is no date given either.

The characteristic, slanted transom visible in right corner belongs to m/s "Władysławowo":
http://www.shipspotting.com/gallery/photo.php?lid=1625177

Other Polish Ocean Lines' ships seen in Gdynia on - apparently - the same day were:

SŁUPSK (IMO 6524242):
http://www.shipspotting.com/gallery/photo.php?lid=1625180

NORWID (IMO 5257919):
http://www.shipspotting.com/gallery/photo.php?lid=1625193

The latter one is very helpful, when it comes to the date, as we know, that "Norwid" was broken up after April 1983.
In the pictures there are trees visible, still with leaves. I think that entire series could be taken latest in late summer 1982.

Of course, the most important information is that pictures were taken from "Vistafjord".
In year 1982, Norwegian American Cruises scheduled "Vistafjord" calls at Gdynia in June and August:
http://www.nytimes.com/1981/10/18/travel/cruises-for-1981-82.html