Day 11 The fine art of wreck discovery: Christian Halverson

Sadly, for those serving Australia in times of war, loss is a profound and shocking reality when the enemy engages. Seventy-four years ago, the SS Macumba, a cargo vessel, was bombed by enemy aircraft and sustained enough damage to cause her to sink. Most of the crew were able to abandon ship, and were rescued. Unfortunately, three crew from the engineering area died in the attack. One man was never recovered.

There had been a few attempts at locating the vessel prior to RV Investigator’s success. I was very fortunate to be there to witness a lot of hard work coming to fruition and the sense of elation as the wreck of the SS Macumba was revealed on a series of screens by the Geophysical Survey and Mapping (GSM) team.

As we “mowed the lawn”, the wonderful technical term for going back and forth across a gridded reference area, the multibeam sonar scanned the shallow depths. Investigator’s navigator, Brendan, had plotted the co-ordinates in liaison with the GSM leader, Stu. The computer-controlled dynamic positioning system was taking us on the grid run and had been doing so for six, maybe eight hours. Many keen onlookers had taken themselves off to bed as the time drifted by. A few had stayed behind keen to give assistance, if needed. What could I do as a school teacher, other than look on in giddy anticipation? A minion is what I could be—providing tea, coffee or delivering a snack to those doing the important work. Only die hard “treasure hunters” remained, plus the real talent doing their job.

The Investigator was turning on the grid when a whole bunch of odd shaped dots came into view and sparked discussion among those in the operations room. Debris field was the consensus.

On the next run past, more of this debris appeared, but it was very regular and not really bits of a damaged ship, quite odd. One of the biologists was pretty sure that this was the right area and suggested that the bridge be informed to swing a little wider on the next pass. It would be up to Amy, the GSM Operator, to make the call. Forty minutes later, as we came up to the area of interest, Amy made the call and the vessel swung just a little wider, maybe an extra 200 metres. We all stared at the screens.

“Oh what’s that?,” Amy asked. The red-orange colour of the sonar image started to have a white blank spot in it. “That’s a ship wreck!,” she yelled punching both arms into the air. She turned to us all with a massive smile and the rest of us jumped around like kids at a party.

Sure enough, on different screens and images, various versions of the SS Mucumba resolved into view. Sonar images, of course, in black and white with coloured contours of different heights of the ship.

The important people were woken from their slumber and informed, communiqués were quickly fired off to the authorities on shore and a proper series of passes north-south, south-north, east-west, west-east was conducted. Eventually, the camera was set up to be lowered carefully over the wreck for a visual identification. It was pretty murky with very low visibility. After a few attempts and with some visuals attained, it was wisely decided not to risk further attempts that might damage the wreck, or the camera.

After a lot of hard work, once again, we saw how all RV Investigator’s crew and science staff work together to add to the knowledge of Australia’s oceans, and in this case, help resolve a 74 year-old piece of our history.