Shack Bay is the second of the two shore access points Parks Victoria names for divers in Bunurong Marine National Park, a small sandy cove between sandstone platforms on the Bunurong Coastal Drive west of Eagles Nest. Its advantage over Eagles Nest is the beach: a sand entry rather than a gully in the rock, which makes it the safer and more forgiving of the two on a marginal day and the better choice for a first dive in the park. Reef runs out from the platforms on both sides of the cove, the same layered Cretaceous sandstone as the rest of the coast, with flat kelp-topped shelves, straight gutters and undercut ledges in 2–12 m.

The life is the marine national park community that has rebuilt itself since protection in 2002: southern rock lobsters in the deeper ledges, Port Jackson sharks resting in the gutters, blue-throat wrasse, zebrafish and sweep in numbers, morwong, leatherjackets and old wives, and the invertebrate colour the park is known for – sea stars, feather stars, sponges, ascidians, large sea snails and crabs on every surface. The sand in the cove holds stingarees and flathead and the weed edge is worth checking for seadragons. Above the water the coast is part of the Yallock-Bulluk Marine and Coastal Park, with the dinosaur-fossil cliffs and hooded plover nesting beaches; on the water, the bay's aspect to the south-west means the same rules as its neighbours – northerly wind, small swell, high tide, early morning – and Parks Victoria's cautions about currents, undertows and unexpected waves apply.

Shack Bay is the Bunurong coast's easiest entry into no-take reef and the natural pairing with Eagles Nest for a two-dive day.

From Inverloch follow the Bunurong Coastal Drive west past Eagles Nest for about 1.5 km to the Shack Bay car park (signposted); from Cape Paterson it is about 6 km east. A track descends to the small beach – 5 minutes with gear. Enter off the sand between the platforms at high tide and swim out to the reef at either side of the cove; exit onto the same beach.

The Bunurong coast faces south-west into Bass Strait and is a surf coast; shore diving is only possible on a northerly or north-easterly wind with swell under about 1 m, at or near high tide for depth over the platforms, and preferably early in the morning. Parks Victoria warns of strong currents and undertows, large unexpected waves and sudden swell changes, so watch the forecast for the day, not just the morning. Visibility is best in autumn after settled weather and drops for days after a south-westerly blow.

Year-round in principle; autumn most reliable.

Enter off the beach at high tide, swim out to the reef on the more sheltered side of the cove and follow a gutter seaward to 8–12 m, exploring the ledges; turn at half gas, cross to the other side of the cove if conditions allow and return along the inner reef to the beach.

No dive shop on the Bunurong coast; sites are dived by independent divers and Melbourne/Gippsland clubs (SEADS – South East Australian Dive Society, Dive La Trobe, VSAG). Nearest air fills in Melbourne's south-east or by arrangement in the Latrobe Valley.