Wild Side is the name Cairns operators give to the exposed eastern side of several reefs, and Milln's Wild Side is listed by Cairns Dive Adventures and Dive the World among the reef's named sites. Because it faces the south-east trade winds, the site is visited only when the weather allows, and that relative rarity is part of its appeal: the coral and fish are less accustomed to divers and the water is often clearer than on the sheltered moorings. Dive the World describes Milln as a reef of large bommies rising from a sandy bottom at around 30 m to within a few metres of the surface, and warns that the surface can be choppy, so divers should limit their time on top.

On the Wild Side those bommies and the reef face attract the bigger residents: whitetip reef sharks, coral trout and peacock groupers, turtles and, occasionally, dolphins passing by. The weather-side corals tend to be robust hard forms shaped by wave energy, with fans and soft corals in the more protected pockets and at depth. Smaller life is also good, with nudibranchs, flatworms, sea stars, eels and painted lobsters in the crevices, and reef squid over the top.

The depth and possible current mean it is best suited to divers with some experience or an Advanced certification. Specific published detail on this mooring is limited, so treat the depths as indicative and follow the guide's briefing. When conditions allow, it gives a quite different impression of the reef from the calm lagoon moorings.

Boat access only. Cairns day boats leave from the Reef Fleet Terminal (1 Spence Street) and the neighbouring Marlin Marina on the city waterfront, with check-in between about 7:00 and 8:00 am; most operators run transfers from city and northern-beaches accommodation, and there is paid parking near the terminal. The run of about 55 km out through Trinity Inlet and across the lagoon to Milln Reef takes around 76 minutes on a fast catamaran and noticeably longer on slower dive boats or into a south-easterly chop.

Wild Side is visited only in calm conditions, usually by Silverswift or on liveaboards; the skipper decides on the day. Enter from the stern and descend quickly as there may be surface chop.

The prevailing south-east trade winds (typically 15-25 knots from April to September) are what limit Cairns outer-reef diving: above about 25 knots trips may be cancelled, and exposed eastern moorings are used only in light winds. Summer northerlies are gentler but make north-facing moorings choppy. Box jellyfish and Irukandji are present from about November to May (stinger suits on every dive), and the cyclone season runs November to April, when a system in the Coral Sea can close the reef for days.

Visibility drops after heavy rain and strong winds; spring is usually calmest and clearest. As its name says, Wild Side faces the prevailing south-easterlies and is only dived on calm days, typically under 10-12 knots; surface conditions can be choppy, so time at the surface should be kept short.

Descend promptly to avoid surface chop, drop to 18-25 m among the big bommies, and work along the reef with any current. Turn at a third of your gas, rise onto the upper reef at 8-10 m for the return, and keep your safety stop close to the line or deploy a marker.

Silverswift and Pro Dive Cairns – occasional, in calm weather only; Milln is also worked daily by Silverswift and Passions of Paradise and on Pro Dive Cairns liveaboards; the mooring used on any day is chosen by the skipper according to wind, tide and other boats