Busselton Jetty is one of Australia's iconic dives. Construction began in 1864 and the first 176 m opened in 1865; extensions continued until the 1960s, giving the present length of 1,841 m, the longest timber-piled jetty in the Southern Hemisphere. The last commercial ship called in 1971 and the jetty closed to shipping in 1972. Cyclone Alby destroyed much of the shore end in 1978 and a fire burned 65 m in 1999, but a preservation committee formed in 1987 led its restoration, completed in 2011. A solar-powered train runs to the end, and the Underwater Observatory, opened in December 2003, takes visitors 8 m down into a chamber with eleven viewing windows.

For divers the attraction is the forest of piles at the jetty's end, encrusted with corals, sponges and other growth and hosting more than 300 marine species; Swan Dive calls it Australia's largest artificial reef. Howies Scuba describes how the jetty broadens near the Observatory, the piles multiply and the area becomes dark and atmospheric. Depths are around 6-9 m, and the sandy sections between pile clusters are sparser but still hold fish and seagrass. Since 2023 an underwater sculpture park has added 13 artworks on the seabed nearby (listed separately).

It is a superb, easy dive for Open Water divers and photographers, and a famous night dive when the piles come alive. Independent divers can walk out with a day pass, but the 1.8 km carry is a real effort. Rules include keeping 10 m from the Observatory.

Busselton is about 2.5 hours south of Perth. Park near the Busselton Jetty Interpretive Centre on the foreshore, buy a $5 dive/snorkel day pass and sign the waiver at the Interpretive Centre. Dive gear is not allowed on the jetty train, so walk it out (20-30 minutes one way) - trolleys can be hired.

Enter via the ladders on the Universal Access Platform on the west side of the jetty, just south of the Observatory gates, down the ramp. Alternatively, Swan Dive runs guided boat dives to the jetty end from the Busselton foreshore, which avoids the long walk.

Geographe Bay is sheltered from the south-west swell, and marinelife.org.au calls the jetty's water very protected, but strong northerly and north-westerly winds (mainly in winter) create chop and stir the sandy bottom. Visibility varies from excellent to murky depending on recent weather. Calm mornings are best; afternoon sea breezes add surface chop for the long walk back.

Enter at the platform ladders, descend to about 8 m and work among the piles around the jetty end, where the structure broadens and the piles multiply. Keep at least 10 m from the Observatory, watch for the large anchor about 7 m south of it, visit the sculpture park, then return to the ladders.

Swan Dive requires night divers to complete a daylight familiarisation dive first and carry an indicator light on the tank.

Swan Dive (Busselton) - daily guided and unguided jetty dives by boat, try dives and night dives (OW or higher; dived within 12 months); Dive Busselton Jetty - scuba, snorkel and SeaTREK helmet diving; Octopus Garden (Bunbury) occasionally. Independent divers can walk out with a day pass.