SM U-2 or U-II was the second ship of the U-1 class of submarines or U-boats built for and operated by the Austro-Hungarian Navy (German: Kaiserliche und Königliche Kriegsmarine or K.u.K. Kriegsmarine). U-2 was designed by American naval architect Simon Lake of the Lake Torpedo Boat Company, and constructed at the navy yard in Pola. She was one of two Lake-designed submarines purchased as part of a competitive evaluation of foreign submarine designs after domestic proposals were rejected by the Navy.