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South Channel Fort

11 Photos, 3 Dives Logged
Depth: 1m, Difficulty: OW
GPS: -38.306783 144.800367 ( 38°18.407'S 144°48.022'E )
Last Edited: 12/24/2022, 4:55:31 PM


South Channel Fort, also known as South Channel Island, is Victoria's only artificial island. It's a 0.7 ha artificial island in southern Port Phillip, Victoria, Australia, 6 km (3.73 mi) north-east of the town of Sorrento. It was part of a network of fortifications protecting the narrow entrance to Port Phillip and used to fire guns, illuminate the channel at night and electronically explode mines under attacking ships coming through the Heads.

South Channel Fort is 122 m (400 ft) long, 76 m (249 ft) wide, and is 6.4 m (21 ft) above sea-level. It was built on a shoal, close to the main shipping channel of Port Phillip, with 14,000 tonnes of bluestone boulders, concrete and sand. It was constructed during the 1880s as part of a defensive strategy to protect and control access by sea to Port Phillip and the cities of Melbourne and Geelong. Above water, the island contains disappearing gun emplacements, a labyrinth of underground passages and magnificent panoramic views over Port Phillip.

The waters are littered with large granite boulders, forming caves and hideaways, caverns, tunnels and the like which make it a photographers dream come true. On the western side of the fort is a small landing jetty, where the water drops down to about 12 metres to a sandy uninteresting bottom. The best diving is certainly in amongst the seagrass or rocky reef between this maximum depth and the Western shoreline of the Fort.

If time permits between tides, the Fort can be circumnavigated underwater at about 5 metres. On the Eastern edge are several large pylons which have collapsed. These were something to do with the second world war and the protective nets that were drawn across the Port Phillip main channel.

The small torpedo bay supports areas of seagrass and many fish can be seen here as well as under the pier. There is also plenty to see on and around the pylons of the jetty. Best to dive the jetty and western side on the ebb tide.

Work began on building South Channel Fort in 1878 with the laying of about 14,000 tonnes of bluestone rocks. The man-made island upon which the fort is built is one of only two islands in Port Phillip and is the only man-made island.

Dive Type: Reef Dive

Imported from The Scuba Doctor


Boat access