Edited sentence: Admiral Hipper later remarked that "To keep valuable ships for a considerable time in a limited area in which enemy submarines were increasingly active, with the corresponding risk of damage and loss, was to indulge in a gamble out of all proportion to the advantage to be derived from the occupation of the Gulf before the capture of Riga from the land side.By19 August, the Russian minefields had been cleared and the flotilla entered the gulf.However, reports of Allied submarines in the area prompted a German withdrawal from the gulf the following day.In August 1915, the German fleet attempted to clear the Gulf of Riga in order to facilitate the capture of Riga by the German army.On 16 August, a second attempt was made to enter the gulf: Nassau and Posen, four light cruisers, and 31 torpedo boats managed to breach the defenses to the gulf.On 17 August, Nassau and Posen engaged in an artillery duel with Slava, resulting in three hits on the Russian ship that forced her to retreat.On the first day of the assault, the German minesweeper T 46 was sunk, as was the destroyer V 99.The German naval force would also lay a series of minefields in the northern entrance to the gulf to prevent Russian naval reinforcements from being able to enter the gulf.The eight battleships were to provide cover for the forces engaging the Russian flotilla.The first attempt on 8 August was unsuccessful, as it had taken too long to clear the Russian minefields to allow the minelayer  to lay a minefield of her own.The fleet that assembled to assault the gulf included Nassau and her three sister ships, the four s, and the battlecruisers , , and.The force would operate under the command of Vice Admiral Franz von Hipper.To do so, the German planners intended to drive off or destroy the Russian naval forces in the gulf, which included the pre-dreadnought battleship Slava and a number of gunboats and destroyers