Shifting her base of operations to Brisbane, "Sailfish" (now under the command of John R. "Dinty" Moore) got underway for her sixth patrol on 13 September and headed for the western Solomon Islands. On the night of 17–18 September, she encountered eight Japanese destroyers escorting a cruiser, but she was unable to attack. On 19 September, she attacked a minelayer. The spread of three torpedoes missed, and "Sailfish" was forced to dive deep to escape the depth charge counterattack. Eleven well-placed charges went off near the submarine, causing much minor damage. "Sailfish" returned to Brisbane on 1 November.