Bayer ya shiga cikin tsakiyar yakin, kuma yana da iyakanceccen aikin sabis. Ayyukan farko da jirgin ya shiga shi ne wani jirgin ruwa mai banƙyama a cikin Arewacin Arewa a ranar 18-19 ga Agusta, 1916, wata daya bayan da aka ba shi izini. Jirgin ya kuma shiga cikin Operation Albion a Gulf of Riga, amma jim kadan bayan da Jamus ta kai hari a ranar 12 ga Oktoba, 1917, Bayern ya yi mined kuma dole ne a janye shi don gyara. An tsare shi tare da mafi yawan jiragen ruwa na High Seas a Scapa Flow a watan Nuwamba 1918 bayan karshen yakin duniya na farko. A ranar 21 ga Yuni, 1919, Admiral Ludwig von Reuter ya umarci a rushe jirgin ruwa; Bayern ya nutse a 14:30. A watan Satumba na shekara ta 1934, an ɗaga jirgin, ya hau zuwa Rosyth, kuma ya rushe. Tambaya: A wane lokaci ne Bayern ya nutse?
Karfe 2:30 na yamma