Sapper Mick Dennis had already fought the Japanese across New Guinea when he paddled ashore on Muschu Island on the night of 11 April 1945. Within hours he was one of eight men being hunted across the island by nearly a thousand Japanese soldiers. Nine days later, after fighting his way through patrols, swimming more than three kilometers of open channel to Wewak, and crossing enemy territory on foot, Dennis walked into an Australian patrol. He was the only survivor. The seven other commandos of Operation Copper had been killed. What Dennis carried back helped keep two Japanese naval guns silent during the Wewak landings a month later.
Operation Copper was one of the last missions run by Z Special Unit in New Guinea. The unit's specialty was clandestine reconnaissance and sabotage behind Japanese lines. By April 1945 the war had moved on to the Philippines and Okinawa, but the Australian 6th Division was preparing to land at Wewak, and Allied intelligence had flagged a specific threat: two 140-millimeter long-range naval guns reportedly still in position on Muschu Island, covering the harbour approaches. If operational, the guns had enough range to fire into the proposed Allied landing areas. They could not stop the invasion, but they could produce significant casualties. Z Special's task was to paddle ashore, confirm whether the guns were still serviceable, capture a Japanese officer for interrogation, and extract.
Eight men went in. Special Lieutenant Alan Robert Gubbay led the patrol. Lieutenant Thomas Joseph Barnes was second in command. Sergeant Malcolm Francis Max Weber, Lance Corporal Spencer Henry Walklate, Signaller Michael Scott Hagger, Signaller John Richard Chandler, Private Ronald Edward Eagleton, and Sapper Edgar Thomas "Mick" Dennis rounded out the team. Walklate, before the war, had played first-grade rugby league for St George. They boarded four Hoehn folboats, two-man collapsible canoes, and were dropped off near the island by patrol boat at night. Unexpected currents pushed the folboats south of the planned landing beach and into a surf break. The canoes swamped. Equipment was lost. The men reached shore and harboured up until morning, hoping their arrival had gone unnoticed.
At daybreak the patrol began its reconnaissance. It did not know that the Japanese garrison had already found some of the swept-ashore equipment further along the coast and had put the island on alert. Muschu Island is roughly ten kilometers long and two across. Nearly 1,000 Japanese troops were stationed on it. Once alerted, they began a methodical sweep. What followed was a running battle over terrain that offered no concealment long enough to matter. The commandos split up. Most never regrouped. One by one they were killed in firefights or captured and executed. Gubbay, Barnes, Weber, Walklate, Hagger, Chandler, and Eagleton all died on the island. Only Mick Dennis, experienced from earlier New Guinea campaigns, managed to evade long enough to reach the eastern shore.
Dennis entered the water and began swimming. The channel between Muschu and the mainland near Wewak is over three kilometers wide, and he was being pursued. He made it across, landed in Japanese-held territory on the other side, and spent the next days moving through enemy lines on foot. On 20 April he walked into an Australian patrol. The information he carried back, about Japanese strength on Muschu, about the positions of the naval guns, about the alerted state of the garrison, proved vital. The guns did not fire effectively during the Wewak landings the following month. The island could not be used to launch counterattacks against Australian forces ashore. Decades later, in 2010 and 2013, MIA Australia expeditions to Muschu recovered the remains of four of the missing commandos. On 12 June 2014, Walklate and Eagleton were buried with full military honours at Bomana War Cemetery outside Port Moresby. The other five are at the Lae War Cemetery. A film based on Dennis's brother Don Dennis's book "The Guns of Muschu" was announced in April 2024.
Muschu Island lies at approximately 3.42°S, 143.58°E in the Bismarck Sea, a few kilometers off the mainland north of Wewak. Its larger neighbor Kairiru Island sits just to the west. Wewak Airport (AYWK) is the nearest active field on the adjacent mainland. From the air, Muschu appears as a low forested island with a narrow channel between it and Wewak's coast; the channel Dennis swam is visible as the stretch of water separating the island from the harbor approaches. The coastal terrain around Wewak is tropical lowland with persistent afternoon convection.