SM UB-53

SM UB-53 was a German Type UB III submarine or U-boat in the Imperial German Navy (Kaiserliche Marine) during World War I. She was commissioned into the Pola Flotilla of the German Imperial Navy on 21 August 1917 as SM UB-53.

She operated as part of the Pola Flotilla based in Cattaro. UB-53 was sunk by mines of the Otranto Barrage on 3 August 1918 at 39.66667°N, 18.66667°W in the Otranto Strait, 10 crew members died.SS Athenia (1914). On 7 April 1918 the submarine saw an airship catch fire accidentally and crash into the sea near the Strait of Otranto with the loss of all hands. It apparently was the German Navy Zeppelin L 59, modified for long-range flights, on the outbound leg of a flight from Yambol, Bulgaria, in an attempt to bomb the Royal Navy base at Malta.

Construction
UB-53 was ordered by the GIN on 20 May 1916. She was built by Blohm & Voss, Hamburg and following just under a year of construction, launched at Hamburg on 9 March 1917. UB-53 was commissioned later that same year under the command of Kptlt. Robert Sprenger. Like all Type UB III submarines, UB-53 carried 10 torpedoes and was armed with a 8.8 cm deck gun. UB-53 would carry a crew of up to 3 officer and 31 men and had a cruising range of 9,040 nmi. UB-53 had a displacement of 516 t while surfaced and 651 t when submerged. Her engines enabled her to travel at 13.6 kn when surfaced and 8 kn when submerged.