The 15 cm SK C/28 was a German medium-caliber naval gun used during the Second World War. It served as the secondary armament for the Bismarck class and Scharnhorst-class battleships, Deutschland-class cruisers and the Graf Zeppelin-class aircraft carriers. A number of surplus weapons were used as coast-defense guns and eight were adapted to use Army carriages and used as heavy field guns as the 15 cm Schiffskanone C/28 in Mörserlafette