Last October, I was lucky enough to cover the thrilling discovery of a lost wreck. One year on, let’s revisit the events of that time…

On August 6, 1943, two Japanese airplanes attacked the SS Macumba, a 2500-tonne merchant ship in waters north of Arnhem Land.

The ship’s engine room was hit, three crewmen were killed, and the boat sank, disappearing into the ocean.

For seventy-four years, despite many searches, its final resting place was a mystery.

Then, in the dead of night on October 4 last year, the mystery was solved.

Wreck mystery solved

On October 3 2017, the crew onboard the CSIRO research boat Investigator was given just twelve hours to find the Macumba. The vessel was passing by the spot where the Macumba had last been seen, and though many previous searches had uncovered nothing, they wanted to give it another try…

The crew used sonar pulses to search the seafloor in a grid pattern. By studying how the pulses bounced back to the top, the team could work out what might be on the ocean’s bottom.

After ten hours of searching, they spotted some “unusual” features. The ship turned for another look.

 

A specialised drop camera was used to photograph the wreck—and this resident reef shark.  Photo: CSIRO Marine National Facility

Midnight success

 

“It was very early in the morning, about 1 am, so everyone was very tired,” says Hugh Barker, voyage manager onboard Investigator. “As soon as [the wreck] appeared on our screens, everyone was celebrating. It was quite special to be the first to see the Macumba in 74 years.”

The team used sonar to map the wreck, which was 40 metres down. They also dropped a camera to photograph it. They discovered the wreck was teeming with life, including “an inquisitive reef shark that seemed to be guarding the site,” Mr Barker says.

The wreck will now be protected as a historic shipwreck.

Frozen in time

Shipwrecks are like time capsules, says Dr Ross Anderson, Curator of Maritime Archaeology at the Western Australian Museum.

“Everything on a shipwreck is frozen in an exact moment of time,” he says. “Shipwrecks, like all archaeological sites and heritage places, are tangible links to our past.”

Dr Anderson’s favourite wrecks are the HMAS Pandora, which ran aground on the Great Barrier Reef in 1791, and the Batavia, Australia’s second earliest shipwreck, which was wrecked off Western Australia in 1629.

Items discovered on both wrecks help us understand how people lived hundreds of years ago.

And there’s still treasure to be found. “There are still many ships lost that were carrying bullion [like precious metals and coins] and other high value cargoes,” he says.

CSIRO’s research vessel Investigator solved the 74-year-old mystery last year. Photo: CSIRO

Searching for treasure

Finding a wreck can be low-tech or high-tech. The divers who re-discovered the Batavia were shown where to look by a crayfisherman who’d spotted the curve of a giant anchor deep in the water.

The Pandora was re-discovered using a magnetometer, which measures changes in the Earth’s magnetic field. In this way, metal objects such as anchors and cannons often help us find lost wrecks, Dr Anderson says.

Other times, colour can point the way. If you’re keen on discovering sunken treasure, keep your eyes peeled for the green of tarnished copper, or the black of crusted silver.

This article first appeared in Crinkling News.