Orzeł-class submarine
 The Orzeł class was a short series of modern submarines built in Dutch shipyards for the Polish Navy in the 1930s. Initially the design was to be built in the United Kingdom but the price proposed was too high and the British Admiralty announced that building a fast submarine with over 20 knots (37 km/h) of surface speed was technically impossible. The two submarines were ordered in De Schelde and Rotterdamse Shipyards the ORP Orzeł (Eagle) and ORP Sęp (Vulture) (four were initially planned).