05/10/2017 12:44 PM AEDT | Updated 09/05/2019 11:49 PM AEST

Shipwrecked WWII Vessel 'SS Macumba' Finally Discovered After 74 Years Off Arnhem Land

Researchers found the merchant ship in the middle of the night, guarded by a reef shark.

National Marine Facility
The search by RV Investigator used the ship's advanced multibeam sonar systems to locate and map the wreck.

A 74-year maritime mystery has finally been solved with the discovery of a merchant ship sunk in Northern Territory waters by Japanese air attack during World War II.

The wreck of SS Macumba was located around 1am on Wednesday morning during a CSIRO targeted survey in the Arafura Sea off the coast of Arnhem Land.

The 2,500 ton steel ship was sunk on August 6, 1943 when two enemy floatplanes attacked at low level and scored a direct hit on the ship's engine room, killing three people.

Investigator, a world-class marine research vessel, used multibeam sonar systems to map and locate SS Macumba, CSIRO reported.

"We discovered the wreck in the middle of the night after about 10 hours of searching, which was lucky as we only had a couple more hours available for the search," said Hugh Barker, Investigator's Marine National Facility Voyage Manager.

"Our drop camera even got a close-up photo of an inquisitive reef shark that seemed to be guarding the site.

A reef shark swims above the remains of the SS Macumba.

Australian War Memorial

"It was a special night for all on board and we are so pleased to find the final resting place of Macumba."