Milkies Reef takes its name from the occupation of the diver who found it, a milkman, and it is one of the least visited of the natural reefs off Glenelg. Like Mac's Ground and Seacliff Reef, it is part of an ancient shoreline that now lies in about 17 m of water, with the reef running north to south across the sandy seabed about 4.5 km south-west of Glenelg. The Sea Wolves and the Dive Shack both rate it among the best local dives for variety, noting that very few divers visit.

The reef is low, with ledges and undercuts along its length, and supports a cover of sponges, ascidians and short algae. Fish life is varied rather than dense: blue devils, cuttlefish, strongfish and silver drummer are regulars, and spider crabs and nudibranchs reward divers who look closely. Crayfish are occasionally found in the deeper undercuts.

Because it sees so little traffic, Milkies is a good place to experience Adelaide's offshore reef ecology without the crowds of the wreck sites. It is also a good training ground for navigation, as the reef is easy to follow once found but there is little else on the surrounding seabed to use as a reference. Divers should carry a compass and a surface marker, and have the boat stay with them.

The dive suits Open Water divers comfortable in offshore conditions and anyone interested in macro life. It works well paired with Mac's Ground, which lies a short distance to the north-west, for a two-reef morning. As with all Adelaide metro sites, the best days follow a spell of easterly winds.

Boat access only. Adelaide Scuba runs its charters from its shop on the Patawalonga at Glenelg North, with the boat leaving through the Patawalonga/Holdfast Shores entrance; private boats launch at the West Beach boat ramp (Barcoo Road end of the West Beach dunes, large trailer park, fee payable) or the Glenelg (Holdfast Shores) ramp. From Glenelg it is a run of about 10-20 minutes due west in flat water.

Use GPS marks: the sites are low-relief and cannot be seen from the surface, and there are no public moorings, so anchor in sand off the structure and leave a boat attendant with a dive flag up because charter and fishing traffic is steady on weekends.

The metro coast faces west into Gulf St Vincent, so the rule is simple: offshore easterly winds flatten the sea and clear the water, while westerlies and south-westerlies build a short, steep chop and stir up the silty bottom. In summer the south-westerly sea breeze usually arrives by late morning or early afternoon, so boats aim to be back in by lunchtime. Northerlies are workable when light.

The gulf has a mixed, small-range tide with 'dodge tides' (neap periods when the water barely moves) that give the easiest diving; strong spring tides can run noticeably across the offshore wrecks. Visibility drops for several days after strong westerly blows and after heavy rain when stormwater and Patawalonga/Torrens outflow reach the coast.

Anchor on the sand beside the reef using GPS, then swim along the reef on a northerly or southerly heading at 16-17 m with the ledge on one shoulder. Turn at half gas and return on the other side, searching the undercuts for crayfish and cuttlefish.

No regular charter; occasional club dives (Sea Wolves, Underwater Sports) and private boats from West Beach.