Sydney Harbour anti-submarine boom net

The anti-submarine net stretched 1,480 meters across Sydney Harbour, constructed with wire and interlocking steel rings suspended between marine piles and buoys.

Installed in 1942 during World War II, the defensive structure faced a notable test when three Japanese midget submarines attempted to infiltrate Sydney Harbour.

The harbor defense system represented Australia's determination to protect its maritime infrastructure while supporting British forces in other war theaters.

Three gates in the barrier regulated maritime traffic, with the western gate reserved for large vessels and the eastern gate serving smaller watercraft.

The first Japanese midget submarine became entangled in the central section of the incomplete net, leading to its crew's decision to self-destruct.

Location: New South Wales

Inception: 1942

GPS coordinates: -33.84110,151.27700

Latest update: May 20, 2025 00:58