[Note 1] The submarine sank 128 ships in 31 patrols for a total of 130,841 GRT and 725 tons,[3] making her the 17th most successful U-boat in both world wars.

The attack on the French auxiliary minesweeper Au Revoir was more successful, sinking the 20-year-old ship of 1,058 GRT, killing 18 crew members.

[4] On 21 March 1916, UB-18 left Zeebrugge again for the Le Havre area, where she successfully attacked ships lying in the roads.

That day, the Flanders Flotilla was formed, and Steinbrinck was awarded the coveted Pour le Mérite order.

[5] Sailing on her last patrol, she was seen off Start Point, Devon by SM U-84 on 4 December 1917, bound for the Western Approaches.

Early on the morning of 9 December she inadvertently surfaced close to the trawler Ben Lawer, which was escorting a coal convoy.