Hi Clive, I fully understand, a convention is a convention. This link shows the RMS Windsor Castle sailing from Cape Town on her final voyage. She is flying the old South African flag, I have a pilot on board flag, a Jolly Roger and a pennant but not the flag of the country of her next port of call ?
https://www.flickr.com/photos/hilton-t/8408900826/

Brett, Forgive me but, flying the flag of your next destination is not something that was just 'done in the old days' it is a requirement. So when the Queen Mary 2 sails from Southampton and is heading directly for New York she will be flying the Stars and Stripes as she departs. Likewise any cruise ship will fly the flag of its next port country.

Thanks Clive, not seen that these days. Much appreciated,
Brett

Brett, No, that is the convention. As you depart you fly the flag of the next country you are sailing to.

Thank you Clive, is it not strange that she is flying the Canadian flag when she is leaving a British port ?

Brett, Yes, she is flying the Canadian flag because (as you'll see from one of the posts below)she was employed on the North Atlantic run from Poland to Canada and after departing Tilbury her next port of call was Montreal.
Bryan, As you will see from the earliest posts below, she was acquired by Greek interests after the Poles withdrew her from service and she served as an accommodation vessel for a while before being placed in lay up and was then sold for scrap.

Do I spot a Canadian flag flying from her mast ???

You've got to remember this all happened over 40 years ago back when any self respecting shipping company flagged their ships in their home country. Stefan Batory was in effect the Polish flagship and Poland was of course a communist country at the time, therefore it would be unthinkable to have her flagged elsewhere.
Times have changed since then, and not really for the better. Witness Cunard and P&O who will tell anyone who'll listen just how fantastically British they are, yet they're US owned, mostly foreign crewed and their ships are all registered in Bermuda!

Thanks James.
Even though she is a Polish ship, it is still unusual for her to be registered there. Most companies use "open flag" registries like Panama and the Bahamas.

Yes, that should be 20 April 1983. An interesting day at the Tilbury Landing Stage as the East German Volkerfreundschaft was also there.

That's because she was a Polish passenger ship, owned by Polish Ocean Lines and used on the North Atlantic run, usually Gdynia–Copenhagen–Rotterdam–London–Montreal–Southampton–Rotterdam–Copenhagen–Gdynia.
She was just about the last real passenger ship on a fixed schedule on the North Atlantic.

Is she flying a Polish flag from her stern?
Not seen this before on a passenger ship.

Clive, she was rotting away at Eleusis as the STEFAN by 1993, surely you meant 1983?