and Nauru for five days without contact. On 9 September, an Allied maritime patrol aircraft mistakenly attacked herwith a depth charge north-northeast of Buka on Bougainville Island in the Solomon Islands at . The depth charge missed by a wide margin, and Peto submerged to and avoided damage. Peto moved to the Truk-Kavieng-Rabaul traffic routes on 20 September, and two days later, sighted five escorted ships headed toward Rabaul. She lost her attack chance at the last moment when the Japanese ships made a radical change of course. While Peto attempted to close for a night attack, an alert escort only away detected her. The Japanese ship opened fire on her, forcing her to crash-dive. From 24 to 26 September 1943, Peto patrolled off the Admiralty Islands without contacts. On 1 October, she sighted three medium cargo ships with only one submarine chaser as escort, and fired six torpedoes, hitting two of the ships. Post-war investigation revealed that Peto sank bpth Tonei Maru and Kinkasan Maru. Peto returned to Brisbane on 21 October 1943. Fourth war patrol Underway again on 14 November 1943 to begin her fourth war aptrol, Peto fueled at Tulagi, and set out for her patrol area on 24 November 1943. On 1 December, she sighted a Japanese convoy consisting of two passenger-cargo vessels with three small escorts. She fired six torpedoes at Konei Maru, which broke up and sank. On 9 December, while firing on a ship in a convoy, her target apparently saw the torpedoes coming and turned toward them to avoid being hit. An escort then drove Peto down and administered a thorough depth-charging. On 19 December Peto received orders to return to Tulagi to embark U.S. Marines, and she landed them on Boang Island in Solomon Islands, before returning to Brisbane on 7 January 1944. Fifth war patrol On 2 February 1944, Peto set course for Tulagi, arriving there on 5 February for fuel before departing the following day for her patrol area. On 10 February Peto headed for a rendezvous with the submarine . On 19 February 1944, Peto attacked a merchant ship with three escorts and one of her torpedoes struck home. The target was immediately engulfed in black smoke and her crew heard depth charges in the distance. Peto surfaced and found the escorts depth-charging Ceros position. After closing Cero slowly, she fired two rounds from her deck gun at