Build for Nitiro Gyogyo and registered in Tokyo, she was launched from Yokohama Dock yard in 1923. She sank on 2 November 1943 during one of the most publicised raids over Rabaul. Captain Charles W. Howe claims responsibility for sinking the Manko Maru. His report stated, “As we dropped into Sampson harbour … I broke away to avoid a collision with another plane…and at a speed of 23- mph, I started a run on a freighter of approximately 1,500-tons. At a range of 800 yards I opened fire. I continued firing until forced to pull up clear of the vessel. A ne thousand pound bomb dropped early skipped into the side of the bat the other banging off the ship`s deck. My gunner reported later that the ship sunk immediately.
Bob Scott tells and interesting story about the Manko Maru , sitting in 26 m in Simpson Harbor. “As Ian Short and I worked as buddies on all dives we often found ways of communicating with each other via taking through our mouthpieces. During an assessment dive on the Manko Maru , I lost a faithful diving knife and it was some hours later that I did a solo dive to locate the knife. Whilst swimming along the deck a voice called my name “Bob” and I immediately swung around expecting my dive buddy t be alongside me Of course he wasn’t, and I was therefore a bit perturbed as I had heard my name clearly and distinctly. I swam on and into open companionway, which led into the interior of superstructure. Inside it was very dark and gloomy so I swung the beam of my underwater torch around in an endeavor to familiarise myself with the interior.
But two facts stuck out - there were o skulls down there , and the Papua medical college had stated that race of origin could not be conclusive without a skull.
“It was like being in a huge derelict hall as all the interior walls had rotted away, and only electrical cables hung from the celling had to be careful not to disturb the sediment built up over thirty years otherwise I stood the chance of not finding a safe exit. I moved further on inside the vessel; until I came upon a large square open hatchway with the remains of rotten stairs heading down t the next deck below. I went down into the shock of my life. There laid out in profusion but with some strange order were dozens of skeletons. After my initial recoil I sensed that something was quite unusual. I withdrew from the vessel, saddened by the trough of trapped sailors not getting on the deck in time before the vessel sank.”
“Skeletons on sunken ships in Rabaul were no unusual in those days, so I thought no more of it. We commenced preliminary work on removing the engine-room components and I found that on this vessel and this vessel alone I would often hear my name called – just “Bob” and nothing else. I mentioned this to Ian on several occasions and we often joked about it but still found it disconcerting. Then one day due to an ill placed underwater explosive charge, we raptured a steam condenser unit and ended up with hundreds of brass tubes scattered like fiddlesticks all over the volcanic sand bottom. Retrieval procedures required that we lay out long wire slings on the bottom and hand place each and every tube across the slings ready for lifting.
With both of us on each end we were placing tubes on upon another in a tedious effort when all suddenly , in the ship towering above us , the noise of a rusty steel door being opened stopped us dead in work. Now let me divert a little. Ships under their own weight start to collapse after time and creek and groan and scream and bang as stresses are build up and released. It is nothing unusual for a diver to live with and sometimes to be scared of noises occurring, things falling, structures collapsing. What was different on this occasion was the noise of someone in steel boots walking along the deck, then opening and shutting anther steel door. The same noises occurred again some five minutes later as the reverse of the doors opening and shutting and footsteps returning along the deck to another door opening and shutting put paid to the dive and we returned to the surface, Ian and I somewhat agitated.“No more jokes about my name being called. We continued our work on the ship with no other strange evens, and finally returned t the area where I had found the skeletons. I then suddenly realised what had been so unusual about my first encounters with them – I had seen no skulls. Somewhat concerned, I removed a femur from one skeleton for medical examination by the Papau Medical College and Port Moresby and reported the find to the District Commissioner. The Medical College said that no country of origin (European or Japanese) could be given without skull, and they asked if they could keep it for for further study.
To this I reluctantly agreed as it was my wish t return it to its rightful resting place. The District commissioner passed on details of the number of skeletal remains within the ship to the War Graves Commission in Canberra.
“So no more was thought of this until some six weeks later when a Roman Catholic priest called at my home and asked of the events of my discovery which had been passed on to him. The priest then told me of his capture by the Japanese when they invaded Rabaul and related a story that during his internment he witnessed the loading of over one hundred Australian prisoners of the war on the Manko Maru only hours prior to the bombing raid of US B-25s and the subsequently sinking of the small ships. Then he stunned me – he said there were no skulls down there. I was completely staggered. How did he know? He then told me that Japanese divers descended onto the wreck shortly after the sinking and beheaded the bodies. Shocked , I asked him why? He said , so they would never be identified. I found this very hard t believe. But two facts stuck out - there were o skulls down there , and the papau medical college had stated that race of origin could not be conclusive without a skull. ”“
Some months passed before I received a summons to see the District Commissioner. He told me of Canberra`s notification to the Japanese of remains on the Manko Maru and of their intention to send a diving team to rabaul to remove all skeletons for retrieval back to japan. When district commissioner heard my story he wired Caberra to tell the Japanese that the vessel had collapsed upon itself and no remains could be removed. I then went out and on my last and final dive I blew in the superstructure and down –deck hatchway with high explosives so that all remains are sealed forever within the ship, be they Australian or Japanese. No one since called my name.
In 1993 a freighter dragged its anchor the wreck of the Manko Maru , ripping out a section of the hull. Human bones were later recovered by divers – but no skulls. ”
Material collected from books :
"Rabauls Forgotten Fleet " and "Hostages to freedom "