She also participated in the Battle of Moon Sound during the German invasion of the Estonian islands in late 1917, where she was damaged.

Bayan was named in honor of the earlier Russian cruiser of the same class captured by the Japanese during the Russo-Japanese War.

[1] Bayan's main armament consisted of two 8-inch (203 mm) 45-calibre guns in single turrets fore and aft.

[3] Anti-torpedo boat defense was provided by twenty-two 75-millimetre (3.0 in) 50-calibre guns; eight of these were mounted in casemates on the side of the hull and in the superstructure.

[5] In early 1917, Bayan was also fitted with two anti-aircraft 76 mm Lender guns, mounted to the sides of the after turret.

The following month, she provided cover as other cruisers laid minefields in the western Baltic Sea, near Bornholm and Rügen Islands on the night of 12 January 1915.

The Russians concentrated on Albatross, which was forced to run aground in Swedish territorial waters, while the faster Augsburg escaped to the south.

Roon lost her wireless aerial due to a near miss; the Russians reported more hits, but not confirmed.

[12] In 1917, Bayan was the flagship of Vice Admiral Bakhirev, who now commanded the naval forces defending the Gulf of Riga.

The shell penetrated the deck near the forward turret and started a fire among the flammable material in the cable compartment that was not extinguished until the next day.

Between the leaky plates and the flooded magazine, the ship took about 1,000 long tons (1,000 t) aboard and her draught forward increased to 26 feet (7.9 m).

[Note 2] Despite her increased draught, Bayan was able to pass through the dredged channel connecting the northern and southern parts of Moon Sound later that day.