During 1942 and 1943 Imperial Japanese Navy submarines conducted a number of patrols along Australia's east coast.

[1] On 16 May 1942 the submarine I-29 attacked the Soviet freighter Wellen 50 miles (80 km) south-east of Newcastle, but did not cause any damage to the ship.

At 10:18 pm the coastal steamer Age was shelled by I-24 35 miles (56 km) south-east of Norah Head; she did not sustain any damage and docked at Newcastle at 1 am the next day.

The purpose of these attacks was to generate what historian David Jenkins has called an "air of disquiet" rather than inflict significant damage on targets in the two cities.

While the Sydney Harbour defences spotted I-24's gun flashes, the submarine ceased its attack and submerged before the Australian gunners could open fire on it.

At this time the submarine was 9 kilometres (5.6 mi) from Newcastle, and was sailing eastwards as her 140 mm (5.5 in) deck gun was stern-mounted.