Kuna is the oldest in-service river icebreaker in the world, built-in 1884 in Danzig. The ship which is sailing on the Oder changed the flag five times. Today, it sails as a museum and training ship, intended for historical and cultural education in the field of the history of waterways, inland navigation, water construction, and ecology, as well as the culture and history of the region in which it has been revitalized.
Initially, the ship was named Ferse (the German name for the Wierzyca flowing into the Vistula – all four ships were named after rivers in the lower Vistula basin). In 1940, Ferse was renamed Marder (marten in German) and, in 1947, retained that meaning in Polish as Kuna. Throughout its service (except for the two-year period after the end of World War II), Kuna did not change its area of operation. After the renovation at the shipyard in Pleniewo, Kuna returned, under the Polish flag, to service in the lower reaches of the Vistula River.
From 2001 to 2004, the locally-established Stowarzyszenie Wodniaków Gorzowskich Kuna (“Kuna Association of Gorzow Watermen”) restored the vessel to its original appearance, collected documentation, and secured the necessary permits to allow a return to active service as a museum ship, providing educational trips.
According to Wikipedia