At my first presentation, to the JSC, I highlighted what I saw as the main operational risks for the search, which were both environmental in nature. My chief worry was the topography where the search would be conducted. It was our rotten luck that Rippon’s position happened to coincide with the physical edge of the Australian continental margin, meaning that we’d be searching in extremely rugged terrain. In fact a recent CSIRO research cruise had produced an excellent bathymetric map for this area, revealing a major submarine canyon shaped like a fan, which the scientists had already provisionally named the Centaur Canyon. The range of water depths over the search area varied hugely, from about 500 to 4,000 metres, but my main concern was how steep some of the walls within the canyon were. Some had slopes greater than forty-five degrees, which would not only be impossible to search using a deep-tow sonar but were potentially dangerous. If the wreck of Centaur had actually sunk in this canyon, we were going to have a hell of a time finding it.
In addition to the rugged terrain, the search area was also the site of the largest and strongest oceanic surface current in all of Australia: the East Australian Current (EAC), a southerly flowing boundary current that was famously portrayed in the animated movie Finding Nemo as the oceanic superhighway that swept two of the central characters, Marlin and Dory, down from the Great Barrier Reef to Sydney. Speeds in the central core of the current average two knots, but can get as high as four under certain conditions. Together, the nasty seabed geology and the fast-flowing EAC was a nightmare scenario for any deep-tow search. I tried to put it into a realistic context for the JSC and said that it would be like conducting an aerial search for lost climbers in the Alps in the midst of a hurricane. If for whatever reason we happened to lose a sonar, I could imagine it being swept away like the two fish from Finding Nemo, never to be found again.
The other issue I had to contend with regarding the EAC was how survival island had managed to drift to the north-east from Rippon’s position to the Mugford rescue position in the face of the southerlyflowing current. This was a conundrum that had stumped others and led people to doubt Rippon’s navigation. Their argument was that it was impossible for the survivors to have drifted in any direction against the EAC, and for that reason Rippon’s position had to be wrong as long as the Mugford position was correct, which everyone assumed it was. This was an overly simplistic view of the EAC, however, as boundary currents are complex, dynamic structures and do not always flow uniformly in one direction. In fact the EAC not only changes its position relative to the coast but can spin off eddy currents that appear to reverse the direction of flow.
Once again I turned to the oceanographer Dr David Griffin of CSIRO to help me understand the possible drift trajectories for survival island, in conjunction with the meteorological hind-casting by Len van Burgel. What I wanted to know was whether there were any oceanographic conditions, given the reconstructed wind field (ten knot winds from 131° true), that could result in a drift to the north-east. In order to come up with the answer, David had to essentially force his computer to search for occurrences throughout the fourteen-year BLUElink database in which a drifting object could have started close to Rippon’s position and ended up close to the Mugford rescue position after thirty-five hours. While there was no way of proving that such conditions actually existed on 14–15 May 1941, I only wanted to know if it was possible, and if it was, the frequency of occurrence.
Fundamentally, in order for Rippon’s position to be correct, there needed to be a cold-core eddy spinning clockwise in exactly the right place at the right time. Such eddy currents do exist, so we weren’t creating a completely new phenomenon. But they are very rare. So rare in fact that of the 5,191 days David searched, he could find only 185 days, or just 3.5 per cent of the time, where these conditions existed. We had pushed the science as far as possible. Although the oceanography couldn’t prove that Rippon was right, it certainly didn’t prove that he was definitely wrong. The only other tantalizing piece of information I possessed to maintain my firm belief in Gordon Rippon was that in describing the conditions at the time of the rescue, one of Mugford’s crew actually noted that ‘a north-easterly current was running’.
After meeting the JSC, I had some free time before the public forum, which I used to visit the Queensland Maritime Museum (QMM), who were helping me with the issue of visibility of the coastal lighthouses. Ian Jempson, ex-RAN, was CEO of the museum, while Jack Duvoisin was its resident lighthouse expert. In previous emails, Ian and Jack had questioned the range at which Gordon Rippon could have seen Point Lookout light. While Rippon’s 3.30 a.m. position for Centaur was based on seeing the light from 23 nautical miles away, Ian and Jack had sent me technical information indicating that the maximum visual range was of the order of 16–17 nautical miles. Because the issue was highly technical and there were still a lot of unknowns, I decided to hold my judgement until we were able to meet face to face. But it was clear from the gist of the emails that both Ian and Jack had serious doubts about Rippon’s navigation based on his ability to see this particular lighthouse.
Like the lighthouses he maintained, Jack Duvoisin spent his life looking out to sea rather than the other way around. Still, he considered himself to be an old salt and I was grateful to have the benefit of the encyclopedic knowledge he had gained from a career working as a lighthouse engineer for the Commonwealth Light Service and the Australian Maritime Safety Authority (AMSA). Although retired, he kept up his passion for lighthouses through his volunteer work at the QMM restoring navigation aids for display. Given the fundamental importance of Rippon’s position being based upon a lighthouse sighting, I would eventually have a long correspondence with both Jack and Ian on the subject, and they were extraordinarily helpful with information right up to the day I left to start the search. I can safely say, however, that what they told me in that first meeting was truly worrying and left me with many sleepless nights over the next six months.
Based on the technical characteristics of the Point Lookout lighthouse alone, and setting aside any personal opinions about Gordon Rippon as a navigator or a man, Ian and Jack both believed that Rippon could not possibly have seen the light as he stated. There were a variety of factors involved, such as the meteorological visibility on the night of the attack, the extent to which background lighting both on land and on Centaur itself made seeing the light more difficult, and whether this light had a loom effect. But the central, overriding problem, which in fairness gave them good reason for their doubts, was that Point Lookout was a relatively low-power light that in theory didn’t have the intensity to be seen from such a long distance away. We had to be certain we were looking at the characteristics of the light as it existed in 1943, but once all this information was retrieved from the archives, it only made their doubts stronger.
The intensity of these old lights is quoted in candlepower or candelas, terms I hadn’t come across since my high-school physics class. The Point Lookout light, which had an elevation of 72.5 metres, used a four-burner acetylene lamp with a luminous intensity of 3,000 candelas. The distance the lights can be seen depends greatly on visibility: basically whether the air is clear, or foggy or full of sea mist. For example, with 10-nautical-mile visibility, Point Lookout can be seen from 11 nautical miles; but at 20-nautical-mile visibility the nominal range increases to 17 nautical miles. There was also the geographic range to consider, which is the calculated line-of-sight distance from the lighthouse to Rippon standing on top of Centaur’s monkey island, where he would have been when taking positions. This distance was 25.15 nautical miles, meaning that even with very good visibility of 20 nautical miles Point Lookout couldn’t be seen from the geographic range.
Later on, Jack provided the diagrams and data to prove his point, which made it very hard for me not to begin doubting Rippon myself. He wasn’t saying it was impossible for Rippon to have seen the light; just that the visibility and all other conditions had to be absolutely perfect on that night. This included a compl
ete absence of background light from land, and being able to turn off Centaur’s, floodlights when he was taking his sights. On balance, Jack thought it was far more likely that the light Rippon had sighted was not Point Lookout, but Cape Moreton, roughly 24 nautical miles to the north. Cape Moreton was a higher lighthouse, at 122 metres, and thus could be seen from further away; most importantly, it had a far more powerful electric lamp, with an intensity of 1,400,000 candelas. At 20-nautical-mile visibility this light could be seen from a distance of 46 nautical miles, well beyond Rippon’s 23-nautical-mile range or even the calculated geographic range of 30.3 miles.
I got this final information from Jack the morning I was scheduled to speak at the public forum, and it made for extremely uncomfortable reading. I had previously considered Gordon Rippon a rock-solid source, and using his navigation as the basis for my search box was going to be a major part of the presentation I planned to give in just a couple of hours. I had no choice but to start considering the implications that Rippon was wrong, and what it meant in terms of the location and size of the search box, water depths, seabed geology, risk of failure, and the increased costs of having to search a larger area. In short, this unwelcome news threw all my preliminary planning up in the air and I had to quickly decide how to present it not only to the relatives and Anthony Crack, but also to the deputy premier of Queensland, Paul Lucas MP, whom I was to brief beforehand and who would be introducing me at the forum.
The last thing I wanted to do was to spook Paul Lucas with this bombshell about Rippon at our first meeting. Although he was standing in for Anna Bligh, he had taken a genuine personal interest in the project and asked good questions as I walked him through all the issues. I explained that a number of the survivors had reported seeing lighthouse lights while they were drifting, and that this would have to be a new avenue of research to see whether any of the sightings were credible and how they related to Rippon’s position. If Rippon did mistake Cape Moreton for Point Lookout, it would also mean that survival island didn’t drift northeast and I wouldn’t have to invoke the rare clockwise eddy to explain this. On the contrary, a sinking position north of Cape Moreton was easier to explain because the drift direction would be south-east, more in keeping with normal EAC flow.
In the end, I got through the day by explaining the preliminary nature of my research and that more work needed to be done. The important thing was to not let this development throw the project off track. It certainly helped that Anthony Crack was unfazed and took it all in his stride. We were developing a very good working relationship and I was impressed by his calm acceptance of the situation: a necessary trait for someone so close to the heart of government.
Within weeks I had a revised research plan that I was working on to resolve this new uncertainty about Rippon’s position. I hadn’t lost faith in Rippon completely, as I had found nothing to change my original opinion of him: that he was an honest and well-regarded navigator who gave truthful answers when debriefed. I would just have to work harder to restore my confidence in his navigation.
Regardless of whether the search was going to be focused on Rippon’s position or not, we still needed to organize a spread of deep-tow sonar and ROV equipment that was capable of working within the full extent of possible water depths from 200 to 4,000 metres. As with Sydney, I advised the government that it would be best to conduct the search in separate phases. Our aim was to start in early December 2009, which meant we had to work fast to select and hire a vessel operator, search contractor and ROV contractor. Because of the extreme depths involved, we expected that the search and ROV contractors would most likely be coming from America, but we hoped to find a suitable support vessel in Australia and ideally one based on the east coast.
Over the next few months while I assisted Anthony Crack’s team with the procurements and provided technical advice to the JSC making the final contractor evaluations, I continued my research into the lighthouse question and began looking into claims made by people who believed they had witnessed the attack from land. Because the search was a hot topic in the local news, people began contacting Anthony’s office claiming they had either seen the explosion or knew where the wreck was. I had the job of investigating these claims and handling the numerous offers from volunteers who wanted to join the search expedition itself. Based on the number of people willing to donate their time as electricians, deckhands, divers or even just to make the tea, the search had clearly caught people’s imagination. As for those who were claiming to have witnessed Centaur exploding, the main thing I had to be wary about was exactly that – people’s imagination.
I took each and every claim seriously, however improbable it seemed. If it was someone saying they knew the position of the wreck, it invariably came from a trawlerman, or someone who knew a trawlerman. A typical example was the claim made by Dr Ross Evans, a Gold Coast GP, who told a reporter that ‘the government will be looking in the wrong direction and waste their money’ if the search was conducted near Rippon’s position. Dr Evans believed the wreck was in the prawn grounds northeast of Cape Moreton. I had heard a similar story from others, telling how the local trawlermen knew of a spot on the sea floor where their nets got caught, which they called ‘the beds’ because they would sometimes pull up rusted iron hospital beds. One could only imagine how hospital beds came to be lying on the sea floor miles from the coast, but as Dr Evans refused to reveal the name of the trawlerman who gave him this information, there wasn’t anything more I could do with it.
The second type of claim was more intriguing, as these were essentially oral testimony from people who were alive at the time and had carried their memories with them their entire adult lives. Most had no documentation or other witnesses to back up what they were telling me, so it came down to how closely their stories fitted the facts and whether I judged them to be reliable. Given how strongly I had rejected the oral testimonies that Glenys McDonald had relied upon for her mistaken belief about the Kormoran—Sydney battle location, I found it slightly ironic that I was now driving around Queensland to hear essentially the same type of accounts.
I needed to be cautious about such conflated memories, where people merged an unrelated experience in their life with a major news event simply because they had occurred at roughly the same time. It wasn’t a question of whether they were being truthful, because in their minds they were absolutely 100 per cent certain of what they were telling me. One elderly man, who had been fifteen at the time, told me about the day he was crabbing with his father in Moreton Bay at 4 a.m. when they both saw a flash on the water to the north-east, between Bribie and Moreton Islands. The man said his memory of the event was ‘as clear as a bell’, but the location he gave me was completely impossible given where the survivors were rescued.
Invariably, the claims I had the most faith in were those in which a second independent witness was involved, or there was some contemporary documentation to back up the story. It also helped when the account had the ring of truth about it. Jean Elder, who lived at Bald Knob Farm, had been eight years old when Centaur was attacked. Although she was in bed at the time, her parents were both up, her father milking the cows and her mother, an early riser, doing the housework. The Elders were both Volunteer Air Observers, with a direct telephone line to report suspicious aircraft. Their farm was located on an elevated mountainside of the Blackall Range, which is known for its spectacular views of the coast, and because their house wasn’t electrified until 1948, it would have been close to pitch dark with no moonlight at the time: an ideal setting to have seen a flash out at sea. This was definitely a claim worth checking, so when Erica Costigan, who had spent twenty-five years documenting every local story about the ship, brought it to me, I agreed to make the long drive up to Bald Knob to hear Jean out.
When we got to Jean’s house, I could see there was real potential in her story being not only true, but also helpful to me in determining the likely location of the wreck. Although she herself had not seen the flash
and was relating a family story that had been with her since childhood, she spoke with belief and a degree of detail that was far better than the other witnesses I had interviewed. Most importantly, she remembered quite clearly her mother reporting the flash by telephone straight away to an official and also referring to it in conversation with a neighbour a few days later. By then it was known that Centaur had been attacked, and Jean’s mother had commented that the two things must have been connected. Standing where she had been when she had seen the flash, I could appreciate what a valuable clue this might be. The view of the sea from the Elders’ house was through a narrow notch above the treeline that was only five degrees wide based on the compass measurements I took. The line of bearing (153° true) to the tip of Moreton Island where the flash was observed, if extended out to sea, was only three nautical miles north of Rippon’s position! Was this the verification I was hoping to find?
This was potentially a very exciting clue because it was so specific in pointing to a relatively precise location at sea. Nevertheless, I only had Jean’s word and needed to somehow corroborate the details of her story. When I looked into the name of the official her mother supposedly called, Eric Gilson Foxton, I did find army records that he was a captain living in nearby Maleny, as Jean had said. She’d thought he might be an intelligence officer, but also added that on the night of the flash he was staying with another family two kilometres away by the name of Kerr. It took me a while, but I eventually tracked down James Kerr in Sydney and went to interview him at his home.
James was just a few years older than Jean, but he confirmed important details of her story: namely, that Eric Foxton had been a great friend of his father’s and was a regular guest at the house, and that the Elder and Kerr houses had been connected by a telephone exchange at Landsborough. James’s mother was also a Volunteer Air Observer, so it made sense for her to regularly talk with Jean’s mother when either of them spotted aircraft. This was as much corroboration as I would ever get, and although I’d hoped for more, it was enough for me to believe that Jean’s story was more than likely to be true. For that reason I would factor it in to where I positioned the search box.
The Shipwreck Hunter Page 33