UB-109 was sunk by mine in the English Channel on 29 August 1918[2] and underwater scanning of the area covered by the Dover Barrage shows her wreck broken in half.[4]
She was built by Blohm & Voss of Hamburg and following just under a year of construction, launched at Hamburg on 7 July 1917. UB-109 was commissioned later the same year under the command of Oblt.z.S. Kurt Ramien. Like all Type UB III submarines, UB-109 carried 10 torpedoes and was armed with a 8.8 cm (3.46 in) deck gun. UB-109 would carry a crew of up to 3 officer and 31 men and had a cruising range of 7,420 nautical miles (13,740 km; 8,540 mi). UB-109 had a displacement of 510 t (500 long tons) while surfaced and 629 t (619 long tons) when submerged. Her engines enabled her to travel at 13.3 knots (24.6 km/h; 15.3 mph) when surfaced and 7.4 knots (13.7 km/h; 8.5 mph) when submerged.