The day started early at 5 a.m. We’d done this same routine only ten days prior but had to cancel as we waited on the wharf—a strong wind warning was issued at 4 a.m. that morning. This time, however, the forecast seemed calm for the day ahead. Excitement could be felt among the team as we began loading the boat in the dark, preparing for our 6 a.m. departure.

 Rebreathers, scooters, drysuits, thermals—and so, so many cylinders. There were so many cylinders that we began loading them into the fish fridges. Before long, we were off, steaming toward the wreck site in anticipation of diving it. Ninety minutes—that’s how long it would take. Ninety minutes to think about what would occur over the following ten hours.

 We arrived at the site just after sunrise. The sun peeked over the horizon, lighting up the water that would be the beginning of our long descent into the abyss. We had been here before. Only four months earlier, Samir and I had come out on a friend’s boat to survey the wreck site, get a feel for the ocean around it, mark it on the echo sounder, and plan what the dive would look like. Finally, the day had come, and we were here.

 We started by throwing in the shot line. I stood next to our skipper, Bobby, discussing the best way to shoot this wreck. Dave and Samir prepared the shot line for our call. We estimated the current to be just under a knot and going north—peculiar for the eastern Australian coast. We decided to position directly over the wreck and drop the shot line, predicting the current wouldn’t be strong enough to move the heavy line with its railroad-track weight.

 That prediction proved wrong. Once the shot was let go, it began its 160 meters journey to the ocean floor. We let it settle and moved the boat to assess where it lay: 70 meters north of the wreck. Not the best, not the worst. We brought some of the shot line in to connect the deco station and drop that in—a procedure we’d done many times before.

 The deco station went in smoothly, but when we checked again, the shot line was now 200 meters from the wreck. In the process of setting the deco station in the current, the shot had drifted further away. The decision was made to bring everything back in and try again, wasting precious daylight. Although we’d arrived early, time was already slipping away. The whole process took us an hour to repeat.

 This time, we changed the method. Bobby positioned the boat on the southwest corner of the wreck. Shot away. Again, we checked: 25 meters—much more suitable. In pitch black, 25 meters still meant you could easily miss the wreck, but it was far better than 70 meters, and given the time, it was as good as we were going to get.

 One wrong move could still undo all our hard work—dragging the deco station and shot line off the wreck with the boat. This time, we threw the whole deco station into the water near the shot line and had one of our support divers swim it over. Scott took the task with complete focus. Swimming against the current with the heavy weights of the deco station, he dragged it over to the shot and clipped it to the main line.

 Final check—had the shot moved? It still showed approximately 30 meters from the wreck. We had the green light.

 We began gearing up. By this point, the sun was high in the sky, and it was beginning to get warm. I was going to be wearing the thermals I had worn on numerous practice attempts, so I knew how hot I was going to get shortly. I had worn all the same gear, in exactly the same way, for numerous dives in preparation for this. Everything fell into place as it should. Dive plans were signed off, and final admin checks were conducted.

 Next, it was time to put the rebreather on and do final checks. But first, Samir and John needed to get into the water. They both had the most bailout gas to carry, which meant they needed a lot of time to get everything on. Finally, it was my turn—JJ on, one bailout cylinder, and the second rebreather, the T-Reb. The scooter and second bailout cylinder were going to get passed to me in the water.

 The cool ocean felt relieving after spending so long on the deck of the boat in thick thermals and heavy equipment. The surface crew quickly passed me my scooter, soon followed by my second stage. Now, at this point, I had all my gear. It took me a few minutes to set everything up how I liked it—computer cables were clear, hose routing was good, cylinders that needed to be bungeed were bungeed, and the T-Reb was sitting how I wanted it, to the side, ready in standby mode.

 In those few brief moments, I had drifted further from the shot. Not to worry—I had done a similar setup dive on a wreck in 75 meters a year prior, in current that was twice as fast. I knew it would be a quick scooter to the shot, and I’d be ready for my descent.

 Samir was having similar issues, and his scooter run along the surface would be drastically longer than mine. It took him an additional ten minutes to reach the shot line, four bailout cylinders and all. By this point, we were all at about 15 meters, waiting patiently. Samir came into view and gave the OK. We were ready to descend.

 The deep blue water looked inviting as we began our descent. Looking down, the abyss seemed to continue forever. It would take about nine minutes to get to 160 meters, but I needed to do some things along the way. I was carrying the second rebreather, and that meant I’d need to do some verification checks on the descent. This would take about a minute for each check, and there were three of them to do—one at 50 meters, one at 100 meters, and the final at 160 meters on the bottom.

 The process would be to stow the scooter, dil flush the second unit, check the cells, unclip the loop, move the NERD on the JJ out of the way, and then remove the JJ loop from my mouth, go to the T-Reb, clear the DSV of water, and take a few quick breaths of the unit. Once the T-Reb was checked, I would go back to the JJ, clip the T-Reb off, unclip the scooter, and the descent would continue. The process would be repeated at 100 meters and on the bottom.

 At 100 meters, the verification went without issues. Towards 130 meters, I started to notice something that would eventually lead to a problem three hours into the dive—cell number 3 began to spike a bit high. Nothing too drastic, but high nonetheless. At 140 meters, I started to notice the ocean floor quickly approaching. I could see John’s light bounce off the sand and also noticed that the shot was not on the wreck. This meant that we might have to search for the wreck.

 In my peripheral vision, I could see a shadow to the left. In that moment, I saw the silhouette of the Nemesis—the wreck we had come for.

 There were a few things that occurred in that moment when I reached 160 meters. In my excitement to see the wreck, I came off the shot line and started scootering towards it, leaving the rest of the team on the shot line as they were placing strobes. I was also suffering from HPNS, which, for me, caused visual disturbances. I felt as though I was on the verge of vertigo. I had previously experienced an intense vertigo episode at 75 meters a number of years ago and knew exactly what that felt like. This gave me a feeling of anxiety, knowing what could happen at this depth. I felt my heart rate begin to increase and had to take three calming breaths to bring myself under control. The feeling of vertigo began to dissipate, and I focused on the task at hand.

 I realised I was not with my team. I turned to face the shot line and saw all three of them there, eager to start exploring the wreck. As soon as I saw them change direction towards me, I slowly turned back towards the wreck and began my exploration. Having studied the 3D model developed by Curtin University from their ROV mission, I knew we were off the port bow of the wreck—or at least what was left of it. This was the first part I approached. I could see it had collapsed, with not much remaining of the bow. Lying on the ocean floor next to it was a derrick crane.

 I turned right and began scootering towards the stern, following the entire port side of the wreck. In that moment, I realised I hadn’t done something I was meant to—verify the T-Reb for the third and final time on the bottom. I stowed the scooter and repeated the process I had done on two previous occasions. It’s an interesting feeling, taking something out of your mouth at 160 meters and placing another rebreather loop in. I had never breathed off a sidemount unit at this depth, and I was curious to see what the WOB would be like. The T-Reb breathed perfectly—indistinguishable from my main unit. Verification complete, I continued my exploration.

 At this point, I was near midships, still on the port side. I continued towards the stern. The stern had also collapsed, with coal cargo strewn across the sea floor. There wasn’t much to see, and Heritage NSW (a government organisation we were assisting with this wreck) had told us they believed the stern was missing. From what I could see, there was nothing to be found, and I certainly didn’t have the time to search for it—the deco was quickly racking up.

 I turned to look at the back of the superstructure and could see some engineering components. Part of me wanted to penetrate and investigate further, but limited bottom time—as well as two rebreathers, two stages, and a scooter—really hampered that idea. I decided against the risk and focused on filming as much as I could from where I was.

 I quickly realised it was probably time to start heading back, and that’s when I signalled John. In my mind, we were still on the far side of the wreck and had to return to the shot line off the bow. I started scootering over the top of the superstructure in anticipation of that. All of a sudden, the strobes flashed in the distance, and I could see the shot line was closer than I’d expected. My mind eased, and I slowed to take in what was beneath me. Looking down into the superstructure from above, my vision was filled by a large funnel and steam relief valves.

 I realised this was also a good opportunity to see the starboard side of the wreck and film the section the ROVs had missed in the 3D model. John and I descended down the starboard side and headed towards the bow. I turned to look at the ship from the front and saw Samir scootering from the superstructure back towards the shot line. I took one final look at the wreck before heading home.

 Dave Apperley was already at the shot line when we arrived and had begun cutting off the railroad track from it. It was time for us to leave the ocean floor and begin our six-hour ascent to the surface.

At the beginning of my ascent, I changed my setpoint from 1.0 to 1.3. The ascent seemed to take forever. I looked at my computer and was surprised to see we were still deeper than 100 m. Dave Apps was using his scooter to help with the ascent.

During the ascent, I noticed that cell 3 began having problems again. It spiked high and was on the verge of voting out. Cells 1 and 2 were just below setpoint, while cell 3 read approximately 1.48. This was still within the voting logic, but it drove the average of all three cells higher.

This created two problems. First, the decompression was now being calculated off a higher average—the deco was 40 minutes shorter than the placebo deco being run off the Shearwater on the T-Reb, which was in Bailout CCR mode. Second, the solenoid wasn’t firing because the average was higher than the setpoint of 1.3.

The solution was to drive the setpoint manually until cells 1 and 2 reached 1.3 (which shortened the deco even further) and then completely disregard the deco on the JJ computers. Deco was instead run off the Shearwater on the T-Reb, ensuring some alignment between what was being breathed and the profile being calculated.

Around three hours into the deco schedule, cell 2 began developing issues on its own. By this point, cell 3 was doing the opposite—showing less and less ppO₂. With two cells now faulty, it was time to come off the JJ. After almost a decade of diving together all over the world, for the first time the JJ could no longer support me. It was time for the T-Reb to pick up where the JJ left off.

By then, I was at about 12 m on the deco station. The T-Reb had been in standby mode and ready. I switched units and continued the remaining three hours of deco without a problem. Meanwhile, the JJ’s cells were completely failing: cell 1 (the only one still functioning) showed approximately 1.16, cell 2 read 0.7, and cell 3 was at 0.4. Complete voting-out logic was flashing on the computer, which became so confused that the deco time climbed by multiple hours. The only way to prevent surface warnings for missed hours of deco was to switch the JJ computers to open circuit bailout.

To keep myself occupied, I had an underwater phone case with my phone pre-loaded with Titanic—perfect entertainment for the remaining hours. I also had an underwater sound system designed and built by Stephen Fordyce, who had generously loaned it to me along with spare batteries for my heated undergarments.

Our support divers made periodic checks on us and collected gear. It was dark by the time Samir and I exited the water. Dave and John had finished deco earlier and were already out. With Scott’s help, we were able to remove all gear in the water and get it onto the boat. By the time we were all out—after 6 p.m.—we were sharing the experience with everyone onboard.

This dive would not have been possible without our incredible surface team: Dive Supervisor and medic Britt Shaw, support diver and doctor Zach Hudson, and support diver Scott Wyatt. Thanks also to skipper Bobby and deckhand Jai from Aquilla Charters in Wollongong.