Dark victory - Operation Jaywick

Australian merchant seaman W R ‘Bill’ Reynolds took possession of a Japanese fishing boat, Kofuku Maru, seized in Singapore when the war with Japan began. He ferried 1,100 evacuees out to Sumatra (then the Dutch East Indies, now Indonesia) as Singapore fell and realised that the boat went relatively unnoticed by Japanese aircraft attacking Singapore, something that would prove valuable in the future.

In Sumatra Reynolds met Major Ivan Lyon, a British Army officer with the Allied Intelligence Bureau, and began hatching a plan for the vessel. The Dutch East Indies surrendered to Japan in March and Reynolds escaped on Kofuku Maru to Ceylon (now Sri Lanka). Meeting up with Lyon again, the pair conceived a covert raid that would shock the Japanese with its audacity and stealth. Kofuku Maru was central to the plan, but it needed a new name. They renamed it Krait, after a small but deadly Asian snake, and the boat was transhipped to Sydney on a P&O steamer.

Called ‘Operation Jaywick’, their plan was to attack Japanese shipping in Singapore Harbour with a team of commandos disguised as the Asian crew of a nondescript fishing vessel – the Krait. They would use folding canoes to infiltrate the harbour and attach limpet mines to the hulls of Japanese ships.

Operation Jaywick was assigned to Z Special Unit (later known as ‘Z Force’), a specialist reconnaissance and sabotage unit formed by British Special Operations Executive officers who had escaped the Fall of Singapore. Although predominantly Australian, Z Special Unit also included British, Dutch, New Zealand, Timorese and Indonesian nationals.

In January 1943 Krait joined 14 men who had trained for Operation Jaywick in secret for three months at remote Refuge Bay on the Hawkesbury River in New South Wales. There they learnt how to fight, kill, wreak havoc and survive. On its way north from Sydney, Krait’s Japanese engine died near Fraser island and it was towed to Townsville to wait for a replacement to be shipped from Tasmania, putting the feasibility of the mission in doubt.

While the Jaywick team waited and continued their commando training, men from Z Special Unit in Cairns led by Lt Samuel Carey made a mock raid on Townsville Harbour on 23 June 1943 attaching dummy limpet mines to 15 ships, shocking Navy personnel and proving that Jaywick could be a success.

Engine problems and general unseaworthiness plagued Krait, delaying the operation. It finally departed from Exmouth, WA, on 1 September 1943. Almost immediately, on-the-spot repairs were needed to repair a broken propeller shaft.

Passing through Lombok Strait on 6 September, Krait proceeded to the Java Sea. There the crew and commandos flew a Japanese ensign, wore sarongs and covered their bodies in ‘Helena Rubinstein’ dark tan makeup to disguise themselves as local fishermen. Whenever possible the crew hid out of sight below decks. After crossing the Java Sea, Krait coasted along the coast of Borneo then headed for the Lingga Archipelago, a cluster of islands south of Singapore. On 18 September, six commandos disembarked in their two-man folding canoes at the island of Pulau Panjang. Krait then left for the relatively safer waters of Borneo with orders to rendezvous with the commandos on the night of 1–2 October.

The commandos island-hopped, paddling their folding canoes northwards through the archipelago arriving at Pulau Dongas on 22 September. There they observed Singapore Harbour traffic, where approximately 59,000 tonnes of Japanese shipping had gathered.

On 26 September, the six men in their three canoes slipped through the night towards their targets.

Lyon and Huston were spotted by a Japanese crewman but ignored, while Davidson and Falls were nearly run down by a tug.

They attached magnetic limpet mines to the hulls of seven ships and fled the anchorage undetected. Early the next morning, six explosions shattered the darkness and six Japanese ships – 35,000 tonnes – were sunk or severely damaged.

One mine had failed to detonate. Krait reached the rendezvous point on 2 October, collected the canoes and their crews and retreated back across the Java Sea through Lombok Strait to Exmouth, arriving on 19 October.

In Singapore the Japanese were stunned by the audacity and success of Operation Jaywick. Not believing that it was an enemy plot, they immediately suspected the civilian population. Local Chinese and Malays, prisoners of war and European civilians topped the list of suspects, and a wave of arrests, torture and executions followed. These reprisals are known in Singapore as the ‘Double Tenth’ after the 10 October, the date that mass arrests by the Japanese Kenpeitai (military police) began.

The misery caused in Singapore was an unintended consequence of Operation Jaywick and has raised questions about its justification, especially given its relatively limited strategic outcomes. The Allies never admitted involvement, probably to preserve Krait’s covert identity for future missions.

As a result the Japanese sought vengeance on Singapore’s civilians.

Yong Su-Moi (Elizabeth Su-Moi Choy) (1910 - 2006) was born in British North Borneo. She moved to Singapore as a young woman to attend Raffles College, and met Choy Kuhn Heng. They married in 1941. 

Following the Japanese occupation of Singapore, Mr and Mrs Choy opened a canteen in Miyako Hospital that supplied daily essentials – such as food and medicine – to patients. Eventually, the canteen also became a conduit between inmates in Changi Prison and the outside world. In the wake of the Double-Tenth incident, Japanese authorities learnt of the couple’s involvement in passing packages, money and messages to Changi prisoners. Both were arrested and Mrs Choy was imprisoned at Singapore’s former YMCA building, where she endured 193 days of brutal interrogation and torture. 

Choy was awarded the Order of the British Empire, Order of the Star of Sarawak, Girl Guides Bronze Medal, and Pingkat Bakti Setia, Singapore.

As the Japanese fishing boat Kofuku Maru, a type common in South-East Asia, it was the ideal candidate for seaborne covert operations. Its teak hull was built in Japan in 1935. It is 21.5 metres (70 feet 8 inches) long, has a maximum breadth of 3.7 metres (12 feet) and a depth of only 2.3 metres (7 feet 6 inches). After Operation Jaywick, Krait operated on a few covert missions off north-west Australia and was present when the Japanese surrendered at Ambon on 12 September 1945. After the war it was sold into the Borneo timber trade. Through the 1950s it worked out of Borneo and was known as Pedang.

In the mid-1950s it was recognised by Australians travelling through the region as Krait, and eventually repatriated to Australia in 1964. It became a Royal Volunteer Coastal Patrol vessel on the NSW coast, before being acquired by the Australian War Memorial (AWM).

Krait is managed for the AWM by the Australian National Maritime Museum and in 2017–2018 the museum undertook a major conservation plan that has restored Krait to its 1943 configuration for Operation Jaywick.

War and Peace in the Pacific 75 a USA Program supported by the USA Bicentennial Gift Fund