Wolfgang Heuer scurries up a flight of steep steps inside the Stephan Jantzen, a Soviet icebreaker ship moored in Rostock, with impressive speed for an old sea dog.

Relied on throughout the Cold War to clear the Baltic of treacherous ice packs, the ship now draws in tourists seeking a fix of “Ostalgie” – the term for nostalgia about life in Communist East Germany (the GDR).

But as Germany holds elections this month, a darker and more recent chapter in Russian history has led to some soul-searching on board this faithful old icebreaker.

Mr Heuer, 55, is one of 30 former sailors who dedicate their retirement years to caring for the Stephan Jantzen, which takes its name from a famed Rostock-born 19th-century sea rescuer. He discusses the ship proudly.

After showing off its well-preserved control room, covered in chunky navigation panels and retro telephones, the retired Navy officer zips up to the bridge and admires the Baltic coastline through a pristine porthole.

“This ship is a symbol of German-Russian cooperation in the Cold War times but also the maritime heritage of Rostock,” Mr Heuer says of the vessel, which some of the Soviet Union’s finest engineers constructed in Leningrad in 1967.

“That’s why we take such good care of it.”