Predominantly Australian, Z Special Unit was a specialist clandestine operation, direct action, long-range penetration, sabotage, and special reconnaissance unit that included British, Dutch, New Zealand, Timorese and Indonesian members, predominantly operating on Borneo and the islands of the former Dutch East Indies.

The unit was created at the suggestion of the commander of Allied land forces in the South West Pacific area, General Thomas Blamey, and was modelled on the British Special Operations Executive (SOE) in London.

[4] It contained several British SOE officers who had escaped from Singapore, and they formed the nucleus of the Inter-Allied Services Department (ISD) which was based in Melbourne.

[4] Several training schools were established in various locations across Australia, the most notable being Camp Z in Refuge Bay, an offshoot of Broken Bay to the north of Sydney, Z Experimental Station (also known as the "House on the Hill" or ZES) near Cairns, Queensland, Fraser Commando School (or FCS) on Fraser Island, Queensland where a commemorative monument stands on the mainland overlooking the island.

[6] In 1943, a 28-year-old British officer, Captain Ivan Lyon of the Allied Intelligence Bureau and Gordon Highlanders, and a 61-year-old Australian civilian, Bill Reynolds, devised a plan to attack Japanese shipping in Singapore Harbour.

[7] Bill Reynolds was in possession of a 21.3 m (70 ft) long Japanese coastal fishing boat, the Kofuku Maru, which he had used to evacuate refugees out of Singapore.

[7] Lieutenant-Colonel G. Egerton Mott, the chief of the Services Reconnaissance Department, suggested that they should test the effectiveness of the plan by making a mock raid on a tightly guarded Allied port.

[8] In January 1943, Lieutenant Samuel Warren Carey, a Z Special Unit officer based at Z Experimental Station, Cairns, Queensland, approached General Thomas Blamey with a proposition for a raid on the Japanese-occupied port at Rabaul, New Guinea.

Lyon and Mott arranged to have Carey's unit perform a mock attack on Townsville, although they were careful not to commit anything to paper.

Townsville was a busy harbour full of troop transports, merchantmen and naval escort vessels, and tight security was maintained due to the constant threat of Japanese air and submarine attack.

[10] At midnight on 22 June 1943, the unit left Magnetic Island and paddled by folboat through the heavily mined mouth of Townsville Harbour.

[10] Operation Scorpion was scrapped due to a lack of submarine transport, but Mott and Lyon had learned many valuable lessons from the raid.

Rimau (Malay for "tiger") was again led by Lieutenant Colonel Ivan Lyon, a British officer on secondment from the Gordon Highlanders.

Their mission was to paddle ashore and reconnoitre the island to determine the status of Japanese defences and validate reports that two 140 mm long-range naval guns were still in position.

[23] He swam the channel to Wewak while being pursued by the Japanese and made his way through enemy territory to eventually meet up with an Australian patrol on 20 April.

[24] The information he returned with proved vital to keeping the guns out of action and in preventing the Japanese from using the island as a launching point for attacks against the Australian forces during the Wewak landings a month later.

[26][27] In late February 2014 it was announced that the remains of former St George first grade rugby league player, Lance Corporal Spencer Henry Walklate, and Private Ronald Eagleton, would be laid to rest in May 2014 with full military honours at the Lae War Cemetery, where the other five men from Operation Copper are buried.

[28] During 1943–45, Z Special Unit conducted surveillance, harassing attacks and sabotage behind Japanese lines in Borneo, as well as the training of natives in resistance activities.

On 25 March 1945, Tom Harrisson was parachuted with seven Z Special operatives from a Consolidated Liberator onto a high plateau occupied by the Kelabit.

[32][33] Major Donald Stott and Captain McMillan were both presumed drowned in heavy seas while going ashore in a rubber boat from the submarine USS Perch (SS-313) in Balikpapan Bay on 20 March 1945.

Warrant Officer Houghton made it to shore in a second boat but was captured ten days later and languished in Balikpapan Prison where he died of beriberi about 20 April 1945.

Their bodies were recovered soon after the Japanese surrender when Lieutenant Bob Tapper, another New Zealander who was working with the War Graves Commission, discovered their remains.

The boats were officially commissioned ships and were outfitted with two 300–320-horsepower diesel engines and armed with one 20mm Oerlikon as well as a number of assorted smaller machine guns.

[35] Of the Snake-class boats that saw service, at least three were used to deploy Z operatives with Hoehn military folboats in enemy occupied areas for reconnaissance or small scale raids.

Those present at the ceremony were original unit members George Buckingham, John Mackay and the then commander of Special Operations of the Australian Defence Force, Major General Mike Hindmarsh.