SM UB-53

She was commissioned into the Pola Flotilla of the German Imperial Navy on 21 August 1917 as SM UB-53.

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.

Like all Type UB III submarines, UB-53 carried 10 torpedoes and was armed with a 8.8 cm (3.46 in) deck gun.

UB-53 would carry a crew of up to 3 officer and 31 men and had a cruising range of 9,040 nautical miles (16,740 km; 10,400 mi).