Briggs Reef lies about 46 km south-east of Cairns, just south of Moore Reef, and Cairns Dive Adventures describes it as an untouched paradise with inside-facing moorings and moorings on its eastern side, which the operators call the Wildside. Depths range from about 5 to 28 m, visibility is typically 12-18 m, and conditions are rated basic, with no significant current. The reef's hallmark is large plate corals, together with good soft- and hard-coral coverage, and the marine life list includes giant clams, octopus, sea turtles, moray eels, anemonefish, several wrasse species and occasional manta rays.

Australian Traveller lists two named sites, The Wedge and One Fin, and Cairns Dive Adventures names the same two as snorkel sites; confusingly, both names also appear in lists for Opal Reef off Port Douglas, so they may have been copied between listings. The main operator here is Pure Snorkelling, a snorkel-focused company, so Briggs is dived less than it is snorkelled, but the combination of calm water, big plate corals and reasonable depth makes it perfectly suitable for Open Water divers on the occasions when diving is offered. The Wildside moorings on the eastern side are used in calm conditions and give deeper water and more fish.

The relatively short run from Cairns, about 55 minutes on a fast boat, is an advantage. Because site-level information is thin, the reef is treated as a whole here; divers should check with the operator which mooring and what depths to expect. Stinger suits are recommended from November to May.

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 46 km out through Trinity Inlet and across the lagoon to Briggs Reef takes around 55 minutes on a fast catamaran and noticeably longer on slower dive boats or into a south-easterly chop.

Briggs is visited by Pure Snorkelling (snorkel-focused day and half-day trips, with introductory diving on some trips); Cairns Dive Adventures gives a travel time of about 55 minutes. 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. Briggs has inside-facing moorings for trade-wind days and eastern 'Wildside' moorings for calm weather.

From an inside mooring, descend onto the coral slope at 5-8 m and follow it with the reef on one side among the large plate corals, dropping to 12-15 m if the group is certified. Return along the upper slope for the safety stop.

Pure Snorkelling – regular snorkel trips (inside and Wildside moorings), limited diving; occasional use by other Cairns operators; trips are snorkel-led, so certified divers should confirm before booking that a dive will be offered on the day; the mooring used on any day is chosen by the skipper according to wind, tide and other boats