The operation's objective was to destroy the Russian naval forces in the Gulf in preparation for landing German troops to facilitate the fall of Riga in the later stages of the Central Powers' offensive on the Eastern Front in 1915.

In early August 1915, several powerful units of the German High Seas Fleet were transferred to the Baltic to participate in the foray into the Riga Gulf.

The intention was to destroy the Russian naval forces in the area, including the pre-dreadnought battleship Slava, and to use the minelayer Deutschland to block the entrance to Moon Sound with mines.

[2] In the meantime, the German armored cruisers SMS Roon and Prinz Heinrich were detached to shell the Russian positions on the Sõrve Peninsula in the south of the island of Saaremaa.

[5] Four large, flat-bottomed barges loaded with German troops attempted to land at Pernau on 20 August, but were repelled by small Russian warships.