Milln Reef is an outer Great Barrier Reef site featuring a diverse topography of shallow reef tops, walls, and pinnacles. The reef starts at 5 metres and descends to 30 metres, with an average depth of 10 metres. Suitable for both divers and snorkellers, the site offers mild currents and visibility ranging from 15 to 20 metres. Access is by boat only, with typical dives lasting 45 minutes. The site is well-suited for beginners, though divers should remain alert to boat traffic during surface ascents. Water temperatures remain pleasant between 25C and 29C throughout the year.

Three Sisters at Milln Reef features three distinct underwater structures comprising reef, pinnacle, and wall terrain. Divers and snorkellers can explore depths ranging from 5 to 30 metres, with an average depth of 26 metres. The site is accessed by boat, with mild currents making it suitable for drift diving. Visibility typically spans 15 to 25 metres. The topography includes walls anchored by gorgonian sea fans and sandy patches inhabited by garden eels. Mid-water columns host schools of fusiliers, snapper, and sweetlips, while the bottom is home to moray eels, lagoon rays, white-tip reef sharks, and sea turtles. Lionfish and stinging jellyfish may be present.

Wild Side at Milln Reef is a boat-accessible site featuring reef walls that descend from 5 to 30 metres. The topography is defined by hard corals providing structure for various reef fish. Divers frequently encounter wrasses, while uncommon sightings include Napoleon Wrasse, Titan Triggerfish, Whitetip Reef Shark, and various butterflyfish and parrotfish species. The site experiences moderate currents, which can intensify near the reef points, requiring proficient buoyancy control. Visibility typically ranges from 15 to 25 metres. Stinger suits are recommended during the stinger season from November to May due to the presence of jellyfish. This site is suitable for intermediate divers and supports night diving.

Boulders is a beginner-friendly boat dive located at Flynn Reef, featuring a combination of reef and wall topography. Divers can explore shallower reef sections starting at 8 metres, with the site extending to depths of 30 metres. Conditions are generally manageable, with mild currents and visibility ranging from 10 to 30 metres. Water temperatures remain warm throughout the year, fluctuating between 25C and 29C. When navigating the site, be aware of sharp coral and rocks near the wall. Divers should shuffle their feet when near sandy or rocky patches to avoid contact with stonefish, and maintain a safe distance from lionfish and sharks.

Ski Slope at Flynn Reef offers a varied profile, dropping from 5 metres to a maximum depth of 27 metres. This site features distinct reef zones and a wall structure, making it suitable for intermediate divers. Access is by boat only, with mild currents facilitating drift dives. Visibility typically ranges between 15 and 30 metres. Water temperatures remain warm throughout the year, though stinger suits are required from November to May due to seasonal jellyfish. The site supports a diverse range of reef fish and invertebrates across its multi-level topography. Guided tours and boat charters are available from Cairns and Port Douglas.

Magic Mushroom is a reef site located at Flynn Reef, offering shallow waters suitable for beginners. Divers and snorkellers can explore depths ranging from 5 to 15 metres, with an average depth of 10 metres. The site is situated 100 metres from the shore and experiences mild currents. Visibility typically ranges between 15 and 30 metres. Water temperatures remain warm throughout the year, fluctuating between 25 and 30 degrees Celsius. When entering or exiting the water, shuffle your feet to avoid sharp coral and rocks. Divers should remain mindful of hand and foot placement on the reef to avoid sea urchins.

Tennis Courts at Flynn Reef is a reef and wall site offering drift diving opportunities. Suitable for intermediate divers, the site features depths ranging from 12 to 25 metres, with an average depth of 20 metres. Visibility typically spans 15 to 20 metres. Divers should expect mild currents, which are best managed by drifting with the flow. Boat access is required for this site, which is located 20 kilometres from shore. Hazards include deep water, lionfish, sharks, and stonefish. Stinger season occurs from November to May, during which full-body stinger suits are recommended. Territorial triggerfish may be present during nesting season.

Flynn Reef is an outer Great Barrier Reef site featuring a diverse topography of shallow coral gardens, walls, and canyons. Depths range from 5 to 30 metres, with an average of 15 metres, making it suitable for both beginners and experienced divers. Access is by boat only, with mild currents that occasionally allow for drift dives. Visibility typically spans 15 to 30 metres. Water temperatures remain warm throughout the year, ranging from 25C to 29C. The site supports night diving and offers facilities including equipment rental and guided tours. Divers should be aware of potential hazards including sharp coral, triggerfish, lionfish, and sharks, as well as seasonal jellyfish.