At Gdynia, Poland is homeport for sailing-ship ZAWISZA CZARNY, owned by the Polish Scouting and Guiding Association (Zwiazek Harcerstwa Polskiego - ZHP). ZAWISZA CZARNY (ex Cietrzew) was built in 1952 at Stocznia Pů?nocna (Northern Shipyard) in Gdansk (the shipyard was founded in 1945 on the location of former DWF Danziger Waggonfabrik, which was located next to Danziger Werft AG).
What is most interesting -
the ship is powered by entirely genuine, probably the only operational U-boat type diesel in the world (edit: the engine was not actually of a U-boat type, being too small). The engine was built at Deutche Werke Kiel "Mak" in 1940. The engine's type is 6Mu423 and its serial number is 7142/7147.