The Shipwreck Hunter

by David L. Mearns

  Mark Dickinson pressed me for a firm opinion about the targets. As much as I wanted to, I couldn’t give him one. The sonar imagery was not conclusive enough, and with only a third of the search box covered, I wasn’t about to change my plan. I told him we needed to run more lines to rule out other high-probability areas and to get a better feel for the seabed surface in case the patch of targets was typical of the geology for this area. In my mind, they could just as well be outcropping rocks as man-made wreckage of some type, but we needed more data to be sure. I decided the sensible thing to do was to continue the search as planned, but if no other suspect targets were found we’d return to this patch and have a closer look with a high-resolution pass.

  Three lines and two days later, only 10 per cent of the search box had yet to be covered and there was less than three days remaining in the ITF budget. The patch of targets we’d detected on day one was still the only possibility we had for Derbyshire, especially as we found it looked less and less like geology the more sea floor we covered. Because time was becoming critical, I suggested we forgo the southernmost line in the box, which all the clues indicated was low-probability, and head straight to the suspect patch to see exactly what it was. We needed to resolve individual targets within the patch, so I took the gamble to narrow the sonar’s swath setting more than I normally would, from 4.8 km to 1.2 km, thus increasing resolution by a factor of four. It meant, however, that the next sonar line had to be perfectly positioned otherwise we wouldn’t be able to produce the detail I knew we needed.

  Getting the sonar towfish in the right position was completely dependent on how well the turn between the two adjacent lines was executed. It took full concentration for at least seven nerve-racking hours while the towfish, dangling from the end of roughly 7,000 metres of cable, was whipped around to the reciprocal course in a slingshot-like manoeuvre. Because a towfish will naturally drop during a turn, keeping a safe altitude above the seabed is paramount. Get the turn wrong and you can easily miss the target and then have to repeat the whole process over again with the loss of at least half a day. But get it badly wrong and you could watch helplessly as your towfish plummets and then crashes into the seabed to be destroyed or never seen again.

  I had already had a very close call on an earlier turn when guiding the towfish over an uncharted submarine mountain on the eastern side of the search box. In that instance the seabed was already climbing faster than I could recover the towfish when the winch controller suddenly packed up and stopped working. As Ron worked feverishly to fix the fault, my eyes were glued to the sonar display showing the trend line of the seabed rising dangerously towards the sonar. A crash was inevitable unless I could do something in the next thirty minutes. With the winch still broken, my only option was to speed the ship up to get the towfish climbing in altitude itself.

  I began by increasing the Shin Kai Maru’s speed in 0.2-knot increments, but with the seabed winning the race, I closed my eyes and increased speed a full knot, up to about 4.5 knots. I didn’t dare go any faster, as drag forces had probably tripled by then and the last thing I wanted to do was overstress a tow cable that we suspected was already weakened following the earlier failure. I also knew that the faster I went, the harder the towfish would hit what was essentially the peak of a mountain. From a high of nearly a thousand metres, it was now just fifty metres off the seabed, and I started to brace myself for the inevitable impact. Just as I had given up hope, Ron called to say the winch controller was fixed and I could start hauling in the cable. How much those last few minutes of recovering cable as fast as I could mattered is hard to say, but when the towfish cleared the rocky peak by only fourteen metres, I was enormously relieved and knew we had dodged a second bullet.

  While the turn to get the sonar on line to scan the patch of targets wasn’t as dramatic, it still raised my pulse more than it needed to. In a bid to save time, I thought I had cut the turn too close and genuinely feared I was going to miss the target area. Sensing the towfish was offline and was only going to sideswipe the patch, I ordered two last-minute course changes that I hoped would be enough to bring the sonar onto the track I wanted. Within minutes of the first targets appearing on my display, I knew I had hit the patch dead centre, exactly where I was aiming, and that it definitely wasn’t geology but was actually an extremely dense field of wreckage. With the Ocean Explorer in exactly the right position, its 120 khz sonar proceeded to paint an incredibly impressive and devastating picture of destruction.

  Our elation at finding Derbyshire soon gave way to shock and disbelief at the condition of her wreckage. This wasn’t how anybody had expected the ship to look when found. Rather than a handful of pieces, her hull was obliterated into literally hundreds of individual fragments strewn across an area measuring 1,300 metres by 900. Although some larger pieces of wreckage stood out, the main story the sonar image told was of a ship that was completely shattered from stem to stern. After days spent discounting the patch because it didn’t look right, there was no doubting any longer that it was Derbyshire, but how did she wind up in such a state? While the search appeared to be over, the sonar images instantly raised new and unforeseen questions about her demise that we hoped to attempt to answer in the few days we had left. Unfortunately, there was one more sting in the tail waiting for us.

  After completing the initial sonar analysis that confirmed Derbyshire’s wreckage, I plotted out a second high-resolution line to collect even more detailed information about the wreck site. The aim of this second line, planned for 600 metres swath, was to collect better images of some of the larger pieces of wreckage so that they could be accurately measured. One huge piece in particular had produced a large acoustic shadow on the first high-res pass, and I suspected this was a major structural section of the ship. A second set of images and measurements might allow it to be identified. Pleased with the day’s results, I went to bed leaving instructions with Craig Bagley to wake me once the next turn was completed and the sonar was on track for the line I’d plotted.

  As the curtain concealing my bunk was drawn back, allowing the harsh glare of the ceiling lights to shake me from the deep sleep I was enjoying, my body clock instantly told me that I hadn’t had the five hours of sleep I’d planned on. Something must be wrong. Craig quickly confirmed my fears, breaking the bad news in his usual direct manner: ‘David, we lost the Ocean Explorer.’

  It is one of the worst feelings ever to lose an important piece of equipment at sea. Old hands in our industry like to say that there are two kinds of sonar operators, ‘those who have already lost sonars, and those who are about to lose one’. The gist being that if you do this job long enough, you will one day experience the embarrassed feeling that goes with leaving vital equipment behind on the seabed. Truth be told, this wasn’t my first loss, but it was very personal because of my connection to the Ocean Explorer. While every piece of lost equipment can ultimately be replaced, it would be impossible to replace the history of success I’d shared with this amazing sonar.

  The loss of the Explorer immediately changed the focus of the project from a shipwreck search to an emergency recovery operation. The decision to bring the Magellan 725 with us now seemed like a masterstroke, as it would give us a real shot at recovering the sonar, thus sparing our blushes back at Oceaneering’s head office. Given that we were planning to make at least one dive with the ROV to take pictures of Derbyshire’s wreckage, as promised to the ITF, it was possible that we could perform both tasks within the remaining time in our schedule, though only just. The main question now was how long it would take to locate the Explorer towfish, if it was even possible.

  While everyone in the team kicked into high gear getting the ROV and associated tools ready for the recovery attempt, no one’s job was more important than that of our lead navigator, Larry Ledet. Relying on a mixture of hard data and pure guesswork, it was left to Larry to calculate whereabouts on the seabed he thought we’d find the 4.2-metre-long torpedo-shaped towfish. Not an easy task
considering the sonar was six kilometres behind the Shin Kai Maru when the cable suddenly snapped. Losing the Explorer was a cruel blow coming so soon after our triumph in finding the Derbyshire. It hardly seemed fair to be thrown into another pressure-filled search straight away.

  The one thing you can count on at sea is that when everything starts to turn against you, bad weather will arrive to really compound the problems. True to form, as soon as we had the Magellan ready to dive, the wind kicked up to a Force 7, putting the recovery operation on indefinite hold. Waiting on weather is always frustrating, but never more so than when time is running out and your company’s million-dollar towfish is still 4,000 metres below you on the seabed. Because of another project starting immediately after ours was scheduled to finish, there was a deadline for getting the Shin Kai Maru back to port, so an extension was out of the question.

  As the hours ticked by and the weather showed no signs of improving, I began to fear the worst: that the Ocean Explorer was staying where it was and we had missed our chance to come home with definitive photographic proof of the Derbyshire. While I was absolutely certain we had found the wreck, I couldn’t expect others to share my confidence in the sonar images. The government had already shown a willingness to either discount or ignore evidence about Derbyshire. I could easily see them doing the same when the ITF presented them with a handful of colourful but inconclusive sonar images without the backup of photographic proof.

  Eventually the weather did improve, allowing us to dive the ROV, although two precious days were lost while we waited. The pressure was now squarely on the shoulders of the two Magellan pilots, Ron Schmidt and Greg Gibson, to find and recover the Explorer sonar as soon as possible. Fortunately, Larry’s estimate of the sonar’s position was spot on, so very little time was expended during the search. The recovery operation proved far more complicated. The main problem was that the buoyant sonar towfish was found floating in the water column while anchored to the seabed by its companion dead-weight depressor. This made cutting the still-connected tow cable and attaching lifting lines almost impossible. It was like trying to wrestle and control a huge bobbing cork. What should have taken minutes took hours, eating deeper into the time we had left. Nevertheless, when Ocean Explorer’s yellow body broke the water’s surface and was craned on board, huge cheers and smiles of relief broke out throughout the ship.

  After calculating how long it would take us to get back to port steaming at full speed, I told Mark we had just enough time to attempt one dive on Derbyshire but that we could spend no more than six hours on the seabed. I recommended we head straight for the largest sonar target in the wreckage field, which I suspected was the bow. I thought this would tell us more about the ship and how it broke up than any other piece of wreckage might. I also thought the biggest object would be the easiest to locate, especially as several other large pieces nearby could be used to navigate the ROV in the right direction.

  Just before the Magellan was launched to begin the dive, I secured in one of its manipulators a small bronze memorial plaque that we were going to place on the wreck on behalf of the DFA, and in the other manipulator a sediment scoop to recover some of Derbyshire’s iron ore cargo, which we expected to find spread across the sea floor. I’d made the scoop out of an empty washing-up liquid bottle I found on the ship, cutting flaps into its base to create a one-way valve that would allow sediments to be forced in but prevent them from escaping afterwards. A lot more thought had gone into the plaque. I’d had it made weeks before we left home and it was inscribed with words of remembrance provided by the DFA. After all the ups and downs over the past seven days, I could scarcely believe we were just hours away from laying the plaque where it would mean so much to the families.

  As the lights of Magellan began to illuminate the seabed at 1.40 a.m. on 8 June, a remarkable sight appeared. At a depth where absolutely no ambient light exists, thousands of tiny twinkling lights shone back at us from the seabed below like a galaxy of stars on a cloudless night. It took a minute or so before we realized what was causing this illusion. Derbyshire’s iron ore cargo was reflecting the lights of the ROV back at us like the facets of a diamond. It was the first sign that we had found the right wreck.

  I purposely had us approach the wreckage field from the perimeter so as not to get confused by the huge amount of debris I knew we would find at the centre. Every sharp edge of fractured steel structure we encountered was a potential hazard that could instantly sever the ROV’s umbilical. This was another reason for not descending straight into the greatest concentration of debris. An hour into the dive, we found our first piece of wreckage. Although it was too small to offer any clues for identification, it was a welded piece of steel plating that showed all the signs of coming from a modern shipwreck. At least we could rule out a wartime wreck, which would most likely be riveted and not welded.

  The path I had plotted to the largest piece of wreckage would take us past three other large pieces, which we could use to vector the ROV the 500 metres it needed to cover along the eastern edge of the wreckage field. As Ron Schmidt flew Magellan along the vectors I’d given him, Larry Ledet and Craig Bagley were on the bridge of the Shin Kai Maru guiding the Japanese captain, with the help of a translator, to make the same movements in lockstep. It was a good plan but we weren’t making the progress I had hoped. We were moving much too slowly; at this rate we were going to run out of time. Like a dog straining on its lead, the ROV was constantly tugging on its umbilical, waiting for the ship to catch up. Two and a half hours after touching bottom we had yet to reach the three large pieces, and everyone was growing increasingly frustrated. Rory Maclean, the ITN reporter, was on a live feed with Jon Snow, the Channel 4 news anchor in London, waiting for me to confirm the exclusive news that the wreck was indeed the Derbyshire. Rory was just about begging me to go on air during the broadcast, but I firmly refused. I wasn’t about to jump the gun with a story of such important national interest before I was 100 per cent certain.

  At 4.30 a.m., the first large piece finally came into view. It was twisted and torn beyond recognition but was clearly wreckage from a large, relatively modern ship. We desperately needed to pick up the pace, and now the ROV began making good progress over the ground. As the size and concentration of wreckage increased, we could all sense we were closing in on something big. Mark Wilson, running the ROV’s sonar, was the first to see it. His screen was filled with an enormous target that was still beyond the sight of the ROV’s video cameras. Everyone who was crammed into the small ROV control room leaned forward in anticipation as Mark rhythmically counted down the closing ranges to the target: 50, 40, 30, 20, 10 metres. Finally Magellan’s lights began to illuminate the enormous target rising out of the gloom. And then it appeared. A colossal wall of steel that could only mean one thing – the DFA’s fourteen-year quest for definitive proof was finally over.

  As Ron struggled to get the ROV closer, white lettering slowly came into focus. Not only had we come straight in on Derbyshire’s port bow, but we were staring at the last five letters of her name – SHIRE. Although the ROV’s taut umbilical prevented us from filming the entire name, there could be no doubt about what was in front of our eyes. We had indeed found the wreck of the MV Derbyshire, 4,210 metres below the spot of angry sea where forty-four unlucky souls had been condemned to their deaths.

  At first it was difficult making sense of the bow’s orientation. It was clearly sitting upright, fairly level on the seabed, but an old photograph had to be consulted to show us which side was which. As Ron manoeuvred the ROV up over the wreck’s side above the forecastle deck, the scene below us came into focus. The double drum mooring winch and spare anchor lashed near the port railing helped us get our bearings straight. The bow had obviously sheared off from the rest of the hull, straight across her entire 44.3-metre breadth from port to starboard. The important question was, at which frame number? To us it looked like the fracture was at frame 339. This was the forward area, along with frame 65
, predicted by Bishop, Price and Temarel to experience peak dynamic stresses. What we had seen of the bow, with all the fractured surfaces around the circumference of frame 339, was enough to suggest that their conclusion about the location of dangerously large stresses in Derbyshire’s hull was valid and warranted further investigation.

  Having satisfied the ITF’s objectives by identifying the wreckage as that of Derbyshire and collecting potentially new and important evidence about what might have caused the ship to sink, it was time to end the dive, but not before completing two final tasks. I had been searching for a good place for us to lay the memorial plaque and spotted a flat open section of the forecastle deck near the spare anchor. As Magellan descended towards this spot, the plaque briefly spun in the current, revealing the writing on both sides. We had all signed our names on the back as a mark of respect for Derbyshire’s victims. On the front were the words requested by the DFA. As Magellan lingered above the deck, having carefully placed the plaque where it will remain as a permanent memorial to the forty-four who perished, the DFA’s prayer stared back at us.

  IN OUR THOUGHTS

  IN OUR HEARTS

  IN OUR AFFECTIONS CONSTANTLY

  AT THE GOING DOWN OF THE SUN

  AND IN THE MORNING

  WE WILL REMEMBER

  THE WHOLE DERBYSHIRE FAMILY

  A long period of silence followed the laying of the plaque, everyone deep in their own thoughts about what we had seen over the past few hours. The horrific destruction of such an enormous ship, many times greater than our own support vessel, was a sobering sight to see. For me, the symbolism in laying the memorial plaque was very powerful.

  Forty-four people had died on this spot, their lives tragically taken in circumstances beyond their knowledge and control. Although their remains were long gone, that didn’t stop the wreck from serving as their grave site. And like any grave, especially one for so many people, it deserved to be marked and remembered eternally.