Lonsdale Arches is a boat-access reef and cave system in Victoria's Port Phillip Heads, where strong currents shape both the dive and the marine life you'll encounter. Depths run from 10 to 18 metres with visibility reaching 10 to 15 metres on good days. The arches and cave structures provide shelter for Southern Blue Devil fish and crayfish, while soft corals and sponges coat the rock surfaces alongside sweeping kelp. Current management is the core skill here - plan your dive around the tide and be prepared for boat traffic in this busy waterway. Cold water and surge in the caves demand attention.

Dragon's Lair is a boat-access reef dive off Victoria that earns its advanced rating through moderate currents and visibility that typically runs 5 to 10 metres. Working depths of 12 to 18 metres give you a reasonable bottom time, but the current demands solid buoyancy control and a good pre-dive briefing on conditions. The reef supports a range of local species, and the slightly challenging visibility adds a searching quality to the dive that rewards patient, methodical divers. Time your descent to work with the current rather than against it, and you'll get far more out of the site.

Foggy Reef earns its name from changeable visibility that ranges from 3 to 15 metres, demanding solid navigation skills and composure when conditions shift mid-dive. Strong currents sweep across this advanced site, creating drift diving opportunities through depths from 8 to 30 metres. The overhead environment adds technical challenge, with cave systems requiring proper training and redundant light sources. The current brings nutrients that feed impressive soft coral colonies and gorgonians, their branches extending into the flow. Sponges cluster in the calmer pockets around the reef structure. Bluedevil fish hover in the mid-water, their electric blue colouration vivid even in reduced visibility. Australian fur seals occasionally investigate divers, particularly curious in summer months. Bottlenose dolphins pass through the area, though encounters remain opportunistic. Cephalopod enthusiasts should check crevices and reef edges for cuttlefish and octopus. Boat traffic overhead requires proper ascent protocols and safety stops conducted with surface marker buoys deployed. The combination of depth, current, overhead environment, and variable visibility creates a genuinely challenging dive. Plan conservatively, maintain buddy contact, and expect conditions to test your advanced training.

The HMAS J2 is a decommissioned Royal Australian Navy submarine sitting upright on the seafloor off Victoria at 37 to 39 metres, making this firmly deep diving territory. The wreck is largely intact, and the combination of confined spaces, potential low visibility down to 1 metre, cold water, and overhead environments demands solid buoyancy control and prior wreck experience. Visibility can reach 10 metres on a good day, but plan for less. Wobbegong sharks rest against the hull, blue devilfish tuck into crevices, and crayfish shelter beneath overhangs. Schools of fish work the water column above, while benthic invertebrates colonise most exposed surfaces. Mild current is typical, though conditions can strengthen.

The SS Coogee sits in deep diving territory at 32 to 35 metres, making this a shore-entry wreck dive best suited to beginners who have already completed some deeper dives with a guide or instructor. Visibility can reach 15 metres, though conditions vary. The wreck itself hosts a colourful mix of marine life including yellow zoanthids, sponges, cuttlefish, catsharks, and the striking blue devilfish. Old wives, butterfly perch, large-toothed beardy, and crayfish are also regularly spotted around the structure. Be aware that currents here can be extreme, and cold water, surge, and boat traffic all require careful attention. Dive with an experienced operator and plan your bottom time conservatively.

The HMAS J5 is one of Victoria's few diveable submarine wrecks, sitting upright on the sand at 34 to 36 metres. The confined spaces and overhead environment demand solid buoyancy control and a technical mindset before you descend. Visibility runs 5 to 10 metres, and moderate current can push through the site, so plan your entry accordingly. The hull is colonised by yellow zoanthids, which provide striking colour contrast against the steel. Seals occasionally visit, adding an unpredictable element to the dive. Nitrogen narcosis is a real consideration at this depth, and decompression obligations can accumulate quickly if you push your bottom time.

The HMAS J4 is one of Australia's few diveable submarine wrecks, sitting upright on the seabed in Victoria's deeper coastal waters at 26 to 27 metres. The hull is well encrusted with kelp and seaweed, giving it a distinctly austere, overgrown character. Visibility ranges from 5 to 15 metres depending on conditions, and strong currents are a consistent feature here, demanding solid buoyancy control and careful dive planning. Surge compounds the challenge near the wreck itself, and entanglement risks from growth and structure mean penetration attempts are not appropriate. This is a boat-access site best suited to experienced wreck divers comfortable in variable, demanding conditions.

Lonsdale Reef combines wreck diving with a working reef in depths from 10 to 45 metres, placing it firmly in advanced territory. Strong currents run through here regularly, so timing your dive around slack water is essential rather than optional. Visibility ranges from 10 to 30 metres depending on conditions, with the clearest water typically arriving in the summer months of December through February. The reef structure supports gorgonians, sponges, and soft coral, and you'll find blue devilfish tucked into crevices if you slow down and look carefully. Crayfish, wrasse, leatherjackets, and sea sweep round out what's a genuinely diverse site. Boat traffic and surge add to the hazard profile, so solid buoyancy control is a prerequisite.