OK, this picture is here for a long time ...
But the correct category is:
Buoy/Lighthouse Maintenance Vessels & Lightships
If one of the admins reads this by chance!
Dornbusch (III) was a Projekt 872 (Finik) Class Buoy Tender built in Poland for the SHD (Seehydrographischer Dienst der DDR) of the former German Democratic Republic.
In Service 17.12.1978-03.10.1990. Then sold and subsequently scrapped in Holland.
Several sister were built for the former soviet union.
They were prepared for military service with four mounts for gun turrets. But I never saw one of them armed.