Get to know some of the must-see coral reef sites on the Great Barrier Reef.

Although the World Heritage-listed Great Barrier Reef stretches over 2300 kilometres along the Queensland coastline, Cairns is considered to be the official gateway to experience this beauty up close. With 3000 separate reefs and over 900 continental islands and coral cays, it’s the world’s largest coral reef system and has a myriad of unique marine life you won’t find anywhere else.

Now we have the big reef covered, it’s good to keep in mind that each of those 3000 separate reefs has its own dive sites – basically the best spots on the reef where you can enter the water.

Ready to snorkel or dive on one of the seven wonders of the natural world, directly from Cairns? Take your pick from these 10 snorkelling and diving spots.

1. Flynn Reef

What it offers: Fantastic coral gardens
Number of dive sites: Nine

Flynn Reef is renowned for its stunning coral gardens. (Image: Tourism and Events Queensland)

Located around 60 kilometres offshore from Cairns, the popular Flynn Reef is known for its stunning coral gardens and diverse array of marine life.

It’s perfect for snorkelling the shallow waters, as well as scuba diving, as the outer edges of the reef drop away to an average depth of 20 metres. Diving conditions are optimal all year round. Tour operators Silverswift and Passions of Paradise visit Flynn Reef.

2. Milln Reef

What it offers: Beautiful, clear waters
Number of dive sites: 11

Spot stunning coral at Milln Reef. (Image: Tourism and Events Queensland)

Also situated on the outer edge of the Great Barrier Reef is Milln Reef, home to some very famous dive sites – particularly Petaj Mooring, where you can often find large schools of bright, colourful fish called sweetlips hanging around, as well as resident turtles and whitetip reef sharks.

The Whale is another fun dive site with a shallow top creating the effect of a whale’s blowhole during low tide. Tour operators Silverswift, Passions of Paradise and the Pro Dive Cairns Three Day Liveaboard Scuba Dive Trip visit Milln Reef.

3. Pellowe Reef

What it offers: Epic wall dives and swim-throughs
Number of dive sites: Two

Find Nemo at Pellowe Reef.

A bit smaller than Flynn and Milln Reef is Pellowe Reef, yet it still packs a punch. One of the dive sites is named Cucumber Alley due to the vast number of sea cucumbers that can be found here. The other dive site, Darth Vader, is named due to long deep valleys and caverns that cover up the light, creating a dark, gloomy (but amazing!) atmosphere.

Due to the smaller size of Pellowe Reef, it’s a lot more exposed to windy weather conditions and can only be accessed in extremely satisfactory weather conditions. Tour operators Silverswift, Passions of Paradise and the Pro Dive Cairns Three Day Liveaboard Scuba Dive Trip visit Pellowe Reef.

4. Moore Reef

What it offers: Operators spend the day here
Number of dive sites: 16

Explore Moore Reef with Sunlover Reef Cruises. (Image: Tourism and Events Queensland)

In the shape of a giant horseshoe with three outer reef pontoon operators parked here, Moore Reef is massive. The pontoons offer an easy way to explore the reef in the protected waters, so families especially love it here.

Onboard a Sunlover Reef Cruise, you can even swirl down a 30-metre spiralling waterslide into the tropical ocean. Tour operators Passions of Paradise, Sunlover Cruises, Great Adventures and Reef Magic visit Moore Reef.

5. Thetford Reef

What it offers: Opportunity to see larger marine life
Number of dive sites: 11

Swim with dwarf minke whales on Thetford Reef.

The two-kilometre-long Thetford Reef site has a bit of everything – great visibility, many coral heads and lots of swim-through canyons and passages to explore.

Cathedral, TUSA Canyons, and Rosco’s are some of its most famous diving sites, and remarkably, whale sharks and dwarf minke whales have been seen passing near this reef. Tour operators Passions of Paradise, Sunlover Cruises, Great Adventures and Reef Magic visit Thetford Reef.

6. Norman Reef

What it offers: Adventure playground for divers
Number of dive sites: 15

Prepare to be amazed by the marine life at Norman Reef. (Image: Jemma Craig/Tourism and Events Queensland)

Similar to Thetford Reef is Norman Reef, a reasonably large reef and one that’s especially appreciated by scuba divers. Here you can explore the many cliffs, caves, swim-through areas and even a little wreck. The reef’s depth also means that it’s home to a range of larger marine life, such as barracudas, trevally and even the odd reef shark.

The waters near Norman Reef are renowned for having superb visibility. Tour operators Passions of Paradise, Reef Experience, Reef Encounter, Divers Den and Down Under Cruise and Dive visit Norman Reef.

7. Upolu Reef

What it offers: A wide variety of marine life
Number of dive sites: Six

Keep your eyes peeled for hawksbill turtles at Upolu Reef.

Upolu is a small, protected lagoon-shaped reef with shallow coral gardens and is an excellent place for first-time introductory diving. You can spot a wide variety of marine life here, such as giant clams, sea cucumbers, nudibranchs, cleaner wrasse, yellowtails, giant trevally and large green mauri wrasse.

Often, hawksbill turtles can be found chewing on the red seagrass found growing between the hard and soft corals of the reef. Tour operators Passions of Paradise, Reef Day Tripper and Ocean Freedom visit Upolu Reef.

8. Saxon Reef

What it offers: Ideal night diving conditions
Number of dive sites: Six

Blacktip sharks come lurking around Saxon Reef.

Large enough to allow up to three boats at a time to moor, liveaboard dive boats often stop at Saxon Reef to give scuba divers a night experience. Reef sharks can be seen at night, and you can expect to see whitetip, blacktip and grey whaler sharks.

During the day, large shallow coral gardens are exposed where many soft and hard corals thrive and can be viewed either snorkelling or diving. Tour operators Passions of Paradise, Reef Experience, Reef Encounter and Divers Den visit Saxon Reef.

9. Hastings Reef

What it offers: A favourite snorkelling spot
Number of dive sites: Nine

Explore the coral-laden Hastings Reef. (Image: Tourism and Events Queensland)

One of the shallower spots on the Outer Reef, a real highlight of Hastings Reef, is its dive site, Fish Bowl. Sitting around five meters under the surface of the water, Fish Bowl is home to plenty of healthy, strong coral growth.

You may even spot turtles at Hastings along with a large school of humphead parrotfish. Tour operators Reef Experience, Reef Encounter and Divers Den visit Saxon Reef.

10. Agincourt Reef

What it offers: Incredible coral formations
Number of dive sites: 30

Off the coast of Port Douglas on the Great Barrier Reef lies the Agincourt Reef. (Image: Tourism and Events Queensland)

Hop onboard a boat ride from Port Douglas to reach Agincourt Reef, a series of many smaller reefs with at least 16 different dive sites. As the reefs are located on the edge of the continental shelf of Australia, the water quality is spectacular, which creates a pristine environment for marine life and coral colonies.

The Gardens is a particularly popular dive site as they are renowned for its brightly coloured reef fish, making it a photographer’s paradise. Tour operators Quicksilver Cruises, Poseidon Dive and Snorkel and Calypso Reef Cruises visit Agincourt Reef.

For more information about how to access these Cairns reefs, check out the best Great Barrier Reef tours in Tropical North Queensland.