On 16 August 1915, a second attempt was made to enter the Gulf: "Nassau" and , four light cruisers, and 31 torpedo boats managed to breach the Russian defenses. On the first day of the assault, the German minesweeper was sunk, as was the destroyer . The following day, "Nassau" and "Posen" engaged in an artillery duel with "Slava", resulting in three hits on the Russian ship that forced her to retreat. By 19 August, the Russian minefields had been cleared and the flotilla entered the Gulf. However, reports of Allied submarines in the area prompted the Germans to call off the operation the following day. 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."