Perched on the edge of the Indian Ocean, Perth is one of Australia's most underrated dive destinations — a sun-drenched city where world-class reefs, marine parks, and historic shipwrecks are never more than a short ride from the waterfront. With stunning reefs, historic shipwrecks, and abundant marine life, diving in Perth offers something for everyone — from beginners to experienced divers, whether you want to explore vibrant coral gardens, dive with sea lions, or discover shipwrecks steeped in history.
Conditions & Seasons
Perth's Mediterranean climate means you can dive all year, with water temperatures ranging from 19°C in winter to 24°C in summer. Peak diving season is typically September to May, with the warmth driven by the tropical Leeuwin Current flowing down from Indonesian waters — bringing with it tropical visitors. Winter months (June to August) see water temperatures drop to 13–19°C, so a 5mm wetsuit with a hood is strongly recommended for cooler-season dives. Unlike northern parts of Australia, Perth enjoys a conservative tidal range, meaning locals can dive any day the swell and wind are fair. Plan a late October or early November trip for a chance to see humpback whale mothers escorting their calves south.
Reefs, Marine Parks & Shore Dives
A short boat ride from Fremantle lies Rottnest Island — a diver's paradise boasting clear waters, mesmerising limestone reefs, and captivating turquoise bays, where you can encounter playful sea lions, graceful rays, and colourful schools of fish at sites such as Crystal Palace, Shark Cave, and Kingston Reef. Rottnest is home to endangered Grey Nurse sharks; at Shark Cave you can see 15 or more congregating at around 24 metres, with the reef itself offering stunning swim-throughs and caves.
With easy shore access and a diverse marine ecosystem, Marmion Marine Park is a favourite among local divers. For an unforgettable wildlife encounter, Shoalwater Islands Marine Park is one of the best places near Perth to dive with Australian sea lions. Keen macro hunters should head to Ammunition Jetty in Cockburn Sound, where divers encounter nudibranchs, seahorses, octopuses, cuttlefish, and a multitude of fish species among jetty pillars teeming with soft corals, sponges, and invertebrates — and the shallow 3–8 m depth makes it a popular spot for night diving and underwater photography.
Wreck Diving
Perth's wrecks are the jewel in the crown. The HMAS Swan — a fully penetrable naval destroyer intentionally scuttled in 1997 off Dunsborough — rests at a maximum depth of around 32 metres and is one of Australia's most impressive artificial reefs, now home to kingfish, batfish, octopuses, and nudibranchs. The HMAS Perth was scuttled in 2001 and sits at 36 metres; this 133-metre-long wreck was carefully prepared prior to sinking, offering excellent penetration opportunities with marine highlights including western blue devils, kingfish, wobbegongs, and large schools of yellowtails. For something closer to the city, the Omeo Shipwreck in Coogee is one of WA's most popular shore dives, offering a fascinating mix of history and habitat.
Marine Life Highlights
Weedy sea dragons, blue-ringed octopus, and wobbegong sharks camouflaged among limestone ledges
Barracudas, buffalo bream, grouper, snapper, and occasional leafy sea dragons around Rottnest Island
Humpback whales, bottlenose dolphins, and Australian sea lions at different times of the year
In summer (November–February), large numbers of manta rays forming mating chains
Western Australian seahorses, wrasse, blennies, sea stars, and eels along shore dive trails
Recommended ISC Certifications
Perth caters to all levels, but to make the most of its deeper wrecks and nocturnal critters, the following ISC courses are well matched to what this region has to offer:
ISC Deep Diver — teaches you to dive efficiently and safely at depths of 30 m or 40 m, essential for wrecks like the HMAS Swan and HMAS Perth.
ISC Wreck Diver — equips you with the skills for safe penetration of Perth's spectacular scuttled vessels, from the HMAS Swan to the Lena and the Omeo.
ISC Night Diver — unlocks a completely different Perth: cuttlefish, octopuses, and basket stars emerge after dark at sites like Ammunition Jetty.
ISC Nitrox Diver — maximise your bottom time on deeper reef and wreck dives, where every extra minute counts.
ISC Boat Diver — a short boat ride is the gateway to Rottnest Island's reefs and caves; this specialty ensures you're comfortable with boat diving procedures before heading offshore.