Plate Top is one of Norman Reef's more varied dives. Divers Den describes a diverse site with sandy passages around shallow areas, clownfish directly beneath the vessel, and a massive mountain range of coral that sits off the main reef for more advanced divers. The site hosts anthias, yellowtail barracuda, anemonefish, gobies, sweetlips, trevally and coral trout, and Divers Den notes that at low tide fish concentrate at the plate's northern corner, while reef sharks, turtles and large schools shelter at the ends of the range.

The name presumably refers to the broad, flat top of the coral range, but the sides of the formation drop into deeper water and are where the more experienced divers spend their time. The shallow areas around the mooring are easy for newer divers and snorkellers, with sandy passages between coral patches, gobies on the sand and clownfish in anemones right under the boat. Out on the range, schools of yellowtail barracuda hang in the current, anthias swarm over the coral, and sweetlips shelter under ledges.

The northern corner at low tide can be spectacular, with fish packed around the point. The site suits a mixed group: novices and snorkellers can stay in the shallows, while divers with an Advanced certification or some experience head out to the range. Good gas management is needed to reach the ends of the range and return, so follow the guide's plan.

Visibility is often 20 m or more, and photographers will want a wide-angle lens for the schools on the northern corner.

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 58 km out through Trinity Inlet and across the lagoon to Norman Reef takes around 82 minutes on a fast catamaran and noticeably longer on slower dive boats or into a south-easterly chop.

Plate Top is a Divers Den mooring, listed by Cairns Dive Adventures as 'Plates'. Enter from the stern platform.

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. Most Norman moorings lie on its protected western side. Divers Den notes that fish concentrate on the plate's northern corner at low tide, so timing the dive around low water is worthwhile.

Check the clownfish below the mooring, then swim out to the coral range and follow it at 12-20 m to its northern corner, where fish gather at low tide. Explore the ends of the range for sharks and turtles, then return through the sandy passages to the shallows for a safety stop.

Divers Den (Reef Quest, Ocean Quest) – regular; other Norman operators occasionally; Norman is also worked by Divers Den (Ocean Quest liveaboard), Reef Experience, Aqua Quest, Down Under Cruise & Dive, Reef Encounter and Passions of Paradise; the mooring used on any day is chosen by the skipper according to wind, tide and other boats