The Drop is on the southern end of Milln Reef, next to The Edge, and Passions of Paradise uses it when the wind swings to the north. The name describes the dive: from the reef edge the bottom falls away at a steep angle, and wind and wave action over thousands of years have carved the reef into interesting formations, with buttresses, gullies and undercuts that give the site more relief than a smooth wall. Hard corals dominate, forming big plate and boulder colonies on the upper slope and more delicate branching forms in the protected gullies.

The steep profile means divers can choose their depth freely, and the carved structure provides plenty of shelter for fish. Expect the usual Milln residents: schools of fusiliers and surgeonfish, parrotfish and wrasse on the slope, coral trout and cod in the undercuts, anemonefish in anemones on the upper reef and reef sharks cruising deeper. Turtles are common in the area.

Because it is used only in northerly winds it is dived less often than the main Milln moorings and tends to feel uncrowded. Published detail beyond the operator's short description is limited, so the depth figures given here are estimates based on the steep profile described. It suits Open Water divers comfortable with a steep slope and is less suitable for snorkellers, who will find the reef flat more rewarding than the drop itself.

It pairs well with a shallower sheltered site such as Club 10 or Three Sisters for the second dive of the day, and its uncrowded feel is a bonus in the busy summer months.

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.

The Drop is a Passions of Paradise mooring used in north winds. Enter from the stern steps and descend to the reef edge.

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. The Drop is a north-wind mooring and is generally used in the northerly breezes of October-March; it is exposed in fresh south-easterlies.

Descend the mooring to the edge and follow the steep drop down to 18-20 m, exploring the carved gullies and buttresses. Turn at a third of your gas and return along the upper slope at 6-10 m to the mooring, with a safety stop over the reef edge.

Passions of Paradise – day trips when north winds make it the sheltered choice; 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