Found this unusual film .
https://www.awm.gov.au/collection/F01976/
Bass strait was mined by German raider ships early in WW2, particulary around the Wilsons Promontory area .
After a ship or two was sunk by the mines . The navy was called in and the old HMAS Orara was mine sweeping the area and she found quite a few German mines .
The movie was shot by somebody with good skills, maybe a professional .
The Orara was a coal burner and it had a leaky hull . I know this because my father was a crew member on the Orara , a stoker .
At one time the, Orara was the sole defender of Port Phillip bay - with a single ancient 4 inch gun and two lewis guns .
Mike