The ship also participated in Operation Albion in the Gulf of Riga, but shortly after the German attack began on 12 October 1917, Bayern was mined and had to be withdrawn for repairs.

After further examinations, the ship was deemed ready for service on 15 July, a month and a half too late for her to participate in the Battle of Jutland.

Ernst Lindemann, who went on to command the battleship Bismarck during her only combat sortie in World War II, served aboard the ship as a wireless operator.

[14] Admiral Reinhard Scheer planned a fleet advance for 18–19 August 1916; the operation consisted of a bombardment conducted by I Scouting Group.

As Moltke and Von der Tann were the only two German battlecruisers still in fighting condition, three dreadnoughts were assigned to the unit for the operation: Bayern and the two König-class ships Markgraf and Grosser Kurfürst.

[15] The makeshift I Scouting Group conducted familiarization exercises on 15 August in preparation for the operation; Hipper was displeased by the slow speed of the battleships and Scheer ordered the unit not to exceed 20 nautical miles (37 km; 23 mi) from the main fleet so as to avoid being cut off by the faster British battlecruisers.

To this end, the Admiralstab (the Navy High Command) planned an operation to seize the Baltic islands of Ösel, particularly the Russian gun batteries on the Sworbe peninsula.

[18] On 18 September, the order was issued for a joint Army-Navy operation to capture Ösel and Moon islands; the primary naval component consisted of the flagship Moltke and III Battle Squadron of the High Seas Fleet.

[19] Opposing the Germans were the old Russian pre-dreadnoughts Slava and Tsesarevich, the armored cruisers Bayan, Admiral Makarov, and Diana, 26 destroyers, and several torpedo boats and gunboats.

Simultaneously, the five Kaisers engaged the batteries on the Sworbe peninsula; the objective was to secure the channel between Moon and Dagö islands, thus blocking the only escape route of the Russian ships in the gulf.

Bayern's role in the operation was cut short when she struck a naval mine at 5:07 while moving into her bombardment position at Pamerort.

[12][21] Despite the damage inflicted by the mine, Bayern engaged the naval battery at Cape Toffri on the southern tip of Hiiumaa.

[22] By 20 October, the naval operations were effectively over; the Russian fleet had been destroyed or forced to withdraw, and the German army held the islands in the gulf.

The operation called for Hipper's battlecruisers to attack the convoy and its escorts on 23 April while the battleships of the High Seas Fleet stood by in support.

Moltke was forced to break radio silence in order to inform Scheer of the ship's condition, which alerted the Royal Navy to the High Seas Fleet's activities.

The Germans reached their defensive minefields early on 25 April, though approximately 40 nmi (74 km; 46 mi) off Helgoland Moltke was torpedoed by the submarine E42.

[26] From 23 September to early October, Bayern served as the flagship of III Squadron, under Vizeadmiral (Vice Admiral) Hugo Kraft.

Scheer—by now the Großadmiral of the fleet—intended to inflict as much damage as possible on the British navy, in order to obtain a better bargaining position for Germany, whatever the cost to the fleet.

[27] Following the capitulation of Germany in November 1918, the majority of the High Seas Fleet was to be interned in the Royal Navy base at Scapa Flow.

On 21 November 1918, the ships to be interned, under the command of Rear Admiral Ludwig von Reuter, sailed from their base in Germany for the last time.

Reuter believed that the British intended to seize the German ships on 21 June, which was the deadline for Germany to have signed the peace treaty.

On the morning of 21 June, the British fleet left Scapa Flow to conduct training maneuvers; at 11:20 Reuter transmitted the order to his ships.

[8][f] Some parts of the ship, including her main battery gun turrets, remain on the sea floor between 38 and 45 m (125 and 148 ft), where they can be accessed by scuba divers.