The Arches Marine Sanctuary is a complex site built around a series of canyon cuts, caverns and arches running through the reef structure, accessed by boat off Victoria's coast. Depths run from 19 to 25 metres in the deeper sections, and visibility is genuinely variable, so plan around conditions rather than expectations. Strong current is a constant factor and surge can make cavern work unpredictable. Kelp, sponges, and sea-fans cover the structure, while gorgonians colonise the deeper walls. Port Jackson sharks and seals are regular sights, and abalone, sea urchins, and sea stars occupy the rocky substrate throughout.

Lake Purrumbete is a volcanic crater lake offering a distinctly unusual freshwater diving experience in Victoria. The site drops to 50 metres, with walls and drop-offs providing genuine deep diving territory that rewards divers comfortable managing depth and buoyancy in dark water. Visibility is highly variable and can be low, so reliable torches are essential rather than optional. Current varies, adding another layer of planning to any dive here. Various reef species inhabit the lake, though conditions rather than marine density define this site. Entry is available from shore or boat, and the site dives year-round.

Lake Bullen Merri is a volcanic crater lake that drops away sharply from shore, offering wall and drop-off diving in an unusual freshwater environment. Depths run from 3 to 50 metres, putting serious bottom time firmly in deep diving territory. Visibility swings considerably, anywhere from 3 to 20 metres depending on conditions, so pick your timing carefully. The lake is stocked with fish, giving you some wildlife interest on the way down. Currents are variable, and the cold water combined with depth means nitrogen narcosis is a real consideration. This is a solid site for intermediate divers who want to practise wall and deep diving without heading offshore.