SM U-30 or U-XXX was a U-27 class U-boat or submarine of the Austro-Hungarian Navy. U-30, built by the Hungarian firm of Ganz Danubius at Fiume, was launched in December 1916 and commissioned in February 1917. U-30 had a single hull and was just over in length. She displaced nearly when surfaced and over when submerged. Her two diesel engines moved her at up to on the surface, while her twin electric motors propelled her at up to while underwater. She was armed with two bow torpedo tubes and could carry a load of up to four torpedoes. She was also equipped with a deck gun and a machine gun.