As part of a group of six submarines selected for Mediterranean service, UB-46 was broken into railcar sized components and shipped to Pola where she was assembled and launched in May 1916, and commissioned in June.

In early December 1916, during the submarine's fifth patrol, UB-46 struck a mine in the Black Sea a short distance from the north entrance to the Bosphorus and sank with all hands.

[6] The Imperial German Navy ordered UB-46 from AG Weser on 31 July 1915 as one of a series of six UB II boats (numbered from UB-42 to UB-47).

[6] The U-boat could carry up to 27 tonnes (27 long tons) of diesel fuel, giving her a range of 6,940 nautical miles (12,850 km; 7,990 mi)at 5 knots (9.3 km/h; 5.8 mph).

Her electric motors and batteries provided a range of 45 nautical miles (83 km; 52 mi)at 4 knots (7.4 km/h; 4.6 mph) while submerged.

[1] As one of six U-boats selected for service in the Mediterranean while under construction, UB-46 was broken into railcar-sized components and shipped overland to the Austro-Hungarian port of Pola.

[9] On 2 August, Bauer achieved his first success in command of UB-46 when the Japanese steamer Kohina Maru was sunk off Alexandria just short of her destination of Port Said.

UB-46 and three of her sister ships in the Pola Flotilla were ordered to Constantinople and, en route, had to navigate through the Dardanelles, which had been heavily mined by the Allies in the middle of 1916.

[18] On 7 December 1916, the stern of UB-46 struck a Russian mine 300 metres (980 ft) off the shore of the Turkish village of Akpınar, approximately 30 kilometres (19 mi) north-west of the entrance to the Bosphorus.