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.

Lonsdale Wall drops from 12 to 45 metres along a vertical face loaded with soft corals, sponges, and gorgonian fans that thrive in the current-swept conditions. This is deep diving territory with genuine consequences: strong currents run regularly, decompression stops are often required, and nitrogen narcosis is a real consideration at depth. Visibility sits between 5 and 10 metres, so methodical navigation matters. The wall and adjacent reef hold blue devilfish tucked into crevices, cuttlefish, boarfish, leatherjackets, and both Port Jackson and swell sharks. Crayfish occupy the cave sections. Boat entry only, with active vessel traffic adding to the pre-dive briefing checklist.

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.

Catch Bag Reef sits at 16 to 18 metres, putting it comfortably within intermediate range while offering enough depth to feel properly immersive. Visibility here can swing dramatically, anywhere from 10 to 30 metres depending on conditions, so timing your dive matters. The reef draws Southern Rock Lobster and abalone, making it a productive site for spotting these species tucked into crevices and ledges. Yellowtail Kingfish also work the water column, often appearing when current picks up. Speaking of which, moderate to strong currents run through this site, so monitor your positioning and plan your entry and exit with the flow rather than against it.

Boarfish Reef takes its name from the long-snouted boarfish you are likely to encounter here, and spotting one is a genuine treat for new divers. The reef runs from 9 to 20 metres, keeping most of the action at comfortable depths while you get your eye in. Visibility ranges from 5 to 25 metres depending on conditions. The current can run strong, so always check before you go in. Slow down and look carefully because this site rewards patient observers with weedy seadragons, seahorses, octopuses, cuttlefish, anglerfish, and stargazers. Blue devil fish and crayfish are also regularly spotted around the reef and cave structure.

Flat Rock is a reef dive off Victoria that rewards beginners with a good mix of marine life at manageable depths. The shallower sections of the reef sit at around 12 metres, with deeper water dropping to 25 metres as you gain experience and confidence. Visibility swings widely from 1 to 20 metres, so conditions can vary noticeably between visits. Keep an eye out for blue devil fish and boarfish sheltering close to the reef, cuttlefish hovering in the open, and Port Jackson sharks resting on the bottom. Swell sharks, rays, soft corals, nudibranchs, and crayfish round out what you might encounter. The current here can run moderate to strong, and surge is worth watching, so go with a guided tour until you know the site well.

Castle Rock is a boat-access reef dive off Victoria that demands respect from the moment you hit the water. Strong currents and surge are the defining conditions here, so solid buoyancy control and situational awareness are non-negotiable. Depths run from 15 to 20 metres with visibility ranging from 5 to 15 metres depending on conditions. The reef holds a good mix of species: Southern Blue Devils occupy crevices alongside crayfish and octopus, while nudibranchs and yellow zoanthids reward anyone who slows down to look closely. Cuttlefish are a reliable sighting, and seals occasionally pass through. Cold water is the norm, so plan your exposure protection accordingly.

The Grotto is a shallow reef and cave dive sitting between 6 and 9 metres, making it accessible for beginners while still offering genuine character. The cave and wall sections give the site its structure, and visibility ranges from 5 to 15 metres depending on conditions. Keep an eye out for southern blue devil fish and boarfish tucked into the reef, along with leather jackets, nudibranchs, rays, and crayfish sheltering in the rockwork. Soft corals add colour throughout. Be aware that current and surge can be strong here, so pick a calm day and stay close to your buddy and guide.