Garden Island lies 5 km off the coast of Rockingham; the two are separated by Mangles Bay at the southern end of Cockburn Sound. Some 10 km long and 1.5 km wide, Garden Island is linked to the mainland by a man-made causeway which leads to the HMAS Stirling naval base. Naturally, the Naval Base on the island's south portion is out of bounds to the public. The northern portion of the island is recreational. Civilians can drive their boats and moor along the beach in an area with picnic facilities.
Like Rottnest Island and Carnac Island, it is a limestone outcrop covered by a thin layer of sand accumulated during an era of lowered sea levels. The Noongar Indigenous Australians tell of walking to these islands in their Dreamtime. At the end of the last glacial period, the sea level rose, cutting the island off from the mainland. For the last seven thousand years the island has existed in relative isolation.
In 1942 the Australian Army commenced heavily fortifying Garden Island with coastal gun batteries, military facilities, additional jetties and searchlights at strategic sites as part of the fixed defences safeguarding the bustling port of Fremantle.
Challenger Battery, consisting of two single 155-millimetre guns, and Beacon Battery, with two single four-inch guns, became operational early in 1942-43 whilst construction went on above and below ground on the heavy Scriven Battery, which comprised two large 9.2-inch guns in single gunhouses. Careening Bay Camp became a major training base for the secretive Services Reconnaissance Department (SRD), also commonly referred to as "Z Special Unit". The base was officially known as the Special Boat Section and was used to train operatives in the advanced use of folboat folding kayaks as well as top secret British midget submarines such as the "Motorised Submersible Canoe" ("Sleeping Beauty"), "Welman" and "Welfreighter" submarines. SRD Parties staging out of Careening Bay Camp were sent on clandestine missions into Japanese-occupied territory.
HMAS Diamantina docking at Garden Island
After the end of World War II, Garden Island's fortifications were abandoned. The present day naval base on Garden Island came into being in the 1970s. The first stage, the construction of a 4.3-kilometre causeway linking the island with the mainland at Point Peron, was completed in 1973. The Naval Support Facility was completed in 1978 and HMAS Stirling was formally commissioned in the same year.
As of 2008, Stirling is home to five frigates and all submarines of the Australian Submarine Service, which is headquartered at the base. A Clearance Diving Team is also based at Stirling.
Since completion of the facility, public access to the island has been restricted to daylight hours. However as of June 2010 public access is not granted to the public in general unless entry is sponsored by the military.
Access by sea is restricted to private boat using moorings, also under curfew conditions. The island is classified as an A-class reserve, and the Navy has undertaken various successful programmes for the removal of introduced animals; all native animals on the island are protected.
The island was marked but not named on Dutch maps in 1658, even though there were three Dutch ships in the area that year: the Waekende Boey under Captain S. Volckertszoon, the Elburg under Captain J. Peereboom and the Emeloort under Captain A. Joncke. However, it was outlined on the charts of the Southland, which were published after Willem de Vlamingh visited the region in 1697.
Jacques Felix Emmanuel, Baron Hamelin was the Captain of the Naturaliste, one of three French ships that visited in 1801 to 1803. He named the island "Ile Buache" after Jean Nicolas Buache, a marine cartographer in Paris. The island was renamed "Garden Island" in 1827 by Captain James Stirling, who "prepared a garden and released a cow, two ewes and three goats in an area of good pasture with good water supply."
It has been widely believed that Stirling chose the name "Garden Island" because he planted a garden there, but Statham-Drew (2003) notes that he used the name well before anything was planted there. She argues that it was so named because the shelter that it provides to Cockburn Sound was reminiscent of the way that the Isle of Wight, then known locally as the "Garden Isle", shelters the waters off Portsmouth.
Mural of Gov. Stirling on Garden Island, 1829
Stirling returned to the area in 1829, claiming Garden Island as part of his grant of 100,000 acres (405 km2), plus any livestock remaining from the previous visit. The first settlement of 450 people was named Sulphur Town. Sulphur Bay and Careening Bay were important anchorage and cargo disembarkation points for ships until 1897 when Fremantle's inner harbour was completed.
In 1907 Peet & Co (now Peet Limited) subdivided eight-three blocks at Careening Bay. After World War I it became a holiday resort with wooden cottages erected at the bay. During World War II, gun batteries were located on Garden Island. These were part of an integrated coastal defence system for Fremantle Harbour facilities.
The biggest battery on Garden Island was the Scriven Battery, fitted with two breech-loading 9.2-inch MkX guns, similar to the Oliver Hill Battery on Rottnest Island. In 1943 building began on a complex of underground tunnels and rooms, included shell stores, magazines, pump chamber and power house, plotting room and command post, and battery observation posts. However, the threat of attack receded as the battery was completed. Resources were allocated elsewhere, and the battery and its guns were placed in reserve. The battery was decommissioned in 1963 and the guns scrapped.
During World War II Careening Bay Camp became a major training base for the secretive Services Reconnaissance Department (SRD), also commonly referred to as "Z Special Unit". The base was officially known as the Special Boat Section and was used to train operatives in the advanced use of folboat folding kayaks as well as top secret British midget submarines such as the "Motorised Submersible Canoe" ("Sleeping Beauty"), "Welman" and "Welfreighter" submarines. SRD Parties staging out of Careening Bay Camp were sent on clandestine missions into Japanese-occupied territory.
Following the war, Garden Island became a holiday resort again and later, the home of the RAN Reserve Fleet.