ended her third patrol by arriving at Brisbane, Australia on 15 February 1943. Her fourth war patrol was conducted in the Bismarcks, Solomons, and New Guinea area, and Guardfish recorded no kills on this cruise, 9 March to 30 April 1943. Leaving Brisbane for the same waters on 25 May 1943, Guardfish sank the transport and hell ship, Suzuya Maru, and damaged another before being forced to dive by aircraft on 13 June. She picked up a surveying party on the west coast of Bougainville on 14 July and returned to Brisbane for refit on 2 August 1943. Sixth and seventh war patrols, August 1943 – February 1944 Guardfish left Brisbane for her sixth war patrol on 24 August 1943, landing a reconnoitering party on Bougainville and then moving into cruising waters. She sank the 5,460 ton Kasha Maru on 8 October and subsequently spent two days as lifeguard ship during the air strikes on Rabaul. Guardfish embarked another reconnoitering party on 19 October at Tulagi, landed them on Bougainville, and took vital soundings in Empress Augusta Bay before re-embarking the Marine party on 28 October. These important missions were carried out two days before the American landings at Bougainville. Guardfish reached Brisbane, completing her sixth patrol on 3 November 1943. On 3 December 1943 Guardfish was damaged in a collision with an unknown tanker. Turning to the shipping lanes between Truk and Guadalcanal, Guardfish began her seventh war patrol on 27 December 1943, sinking 10,024 ton oiler Kenyo Maru on 14 January 1944. She then closed Truk and sank the destroyer on 1 February in an attack on a convoy. After serving briefly as lifeguard ship off Truk she arrived at Pearl Harbor 18 February and from there returned to San Francisco for repairs nine days later. Eighth and ninth war patrols, June – October 1944 Guardfish again put to sea from San Francisco and arrived at Pearl Harbor on 1 June. She then joined submarines , , and to form the coordinated attack group known as the "Mickey Finns", commanded by Captain W. V. O'Regan in Guardfish. The submarines patrolled the shipping lanes around Formosa with spectacular success, Guardfish sinking 5,863 ton auxiliary Mantai Maru, 2,838 ton cargo ship Hizan Maru, and 5,215 ton cargo ship Jinsan Maru southwest of Formosa on 17 July. After damaging another freighter 18 July, Guardfish sank the cargo ship the next day,