12 Great Barrier Reef facts to help you plan a bucket list adventure

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Soak up every extraordinary inch of the world’s largest coral reef system with our round-up of the most fascinating Great Barrier Reef facts.

Sure, you can join a whistlestop tour or marvel at it from parts of Queensland’s mainland, but nothing immerses you in the enchantment of the Great Barrier Reef like scratching beyond the surface. The world’s largest living entity, recently nominated for the United Nations Environment Programme’s Lifetime Achievement Award (typically reserved for humans), is a profoundly complex and captivating natural wonder stretching across more than 348,000 square kilometres.

Filled with thousands of individual reefs and more than 900 islands, it’s a bucket list destination that must be experienced (several times over) to grasp its magnitude. From the environmental factors that threaten its existence to the string of world-class snorkelling and diving spots it boasts, reading up on essential Great Barrier Reef facts will only enhance your visit. Here, we round up the basics. 

1. It’s estimated to be roughly 500,000 years old

the white sand Low Isles coral cay from above

Larger coral reefs surround the white sand Low Isles coral cay. (Image: Tourism and Events Queensland)

According to multiple scientific reports, including one from the Great Barrier Reef Foundation, which was solely established to preserve and protect it, early sightings date back to more than 500,000 years ago — and potentially as far back as 600,000 years.

In terms of how it looks today, a major growth spurt occurred anywhere between 4,000 and 9,000 years ago, pushing new coral colonies to spread across the region. No matter how you carve it, the Great Barrier Reef is an ancient wonder.

2. You can see the Great Barrier Reef from space

an aerial view of Heron Island, Great Barrier Reef

The 2300-kilometre-long Great Barrier Reef is visible from space. (Image: Tourism Australia)

The largest living structure on our planet, the Great Barrier Reef can be spied from as high up as space. It’s bigger than two Aussie states combined and larger than the entirety of Italy. Sweeping the Coral Sea from Bundaberg to Cape York, its expanse also sinks to extreme levels, notching up an average depth of 35 metres.

3. The best time to visit is during the dry season

a huge manta ray swimming with divers, Great Barrier Reef

Chance upon a majestic manta ray on Lady Elliot Island. (Image: Tourism and Events Queensland)

While there’s never a terrible time to visit the Great Barrier Reef, you’ll likely experience less rain if you go during its dry season. Running from May to October, you’ll run into more clear skies above and fewer postponed boat excursions down low.

On the other hand, while November to May boosts a high chance of rain, water clarity is next level during these months. Epic manta ray and sea turtle selfies or guaranteed sunny backdrops? The choice is yours.

4. It’s a UNESCO World Heritage Site

an aerial view of the reefs surrounding Hamilton Island, Great Barrier Reef

Hamilton Island is a gateway to the magnificent reef. (Image: Tourism and Events Queensland)

In 1981, the Great Barrier Reef was officially crowned a UNESCO World Heritage Site, added to the World Heritage List for its ‘Outstanding Universal Value’. So what? Well, it’s significant as it propels support for the reef’s preservation and reiterates its cultural value. Other global sites include the Pyramids of Egypt, the Grand Canyon in the USA and the Galápagos Islands in Ecuador — so we’re hanging with pretty solid company.

5. It is globally renowned for its biodiversity

a sea turtle swimming beneath Frankland Islands, Great Barrier Reef

The Reef is home to six out of the world’s seven sea turtle species. (Image: Tourism Australia)

A staggeringly complex collection of more than 300 coral reefs, the Great Barrier Reef is home to more than 400 coral species, 1,500 fish species, six of the world’s seven marine turtle species, 2,000 square kilometres of mangroves and so much more. It supports much of the marine life Australia is renowned for, including dugongs. The reef is home to major dugong feeding grounds, creating one of the world’s largest dugong populations.

While we’re throwing out impressive numbers, add 30 species of whales and dolphins, more than 240 bird species and thousands of plant species to its roll call before you even consider counting each coral cay’s unique flora and fauna.

6. It’s threatened by a string of natural factors

fishes swimming around vibrant coral reefs, Lady Musgrave Island

Coral bleaching continues to threaten the Reef’s marine species. (Image: Tourism Australia)

Sadly, natural elements serve as the biggest threat to the Great Barrier Reef. Rising sea temperatures affect coral livelihood and often lead to coral bleaching, where coral struggles to recover. Additionally, marine species are forced to search for cooler waters, meaning there’s impossible competition for food and shelter.

Declining water quality from land-based run-off is also bringing pesticides and other pollutants into the sea.

7. It’s also threatened by human interference

a boat conducting a Great Barrier Reef tour

Sustainable tours allow you to explore the reef responsibly. (Image: Tourism Australia)

Responsible commercial fishing practices are crucial in keeping the Great Barrier Reef safe. These practices, which include limiting fishing licences and restricting vessel capacity and sizes, work to prevent overfishing and the fishing of endangered species.

Additionally, pollution, plastic particularly, is also a key driver when it comes to the reef’s decline. Plastic effortlessly smothers seagrass beds and corals, blocking the sun from nourishing it and encouraging the growth of invasive dangers like the crown-of-thorns starfish.

8. It’s home to some of Australia’s most pristine islands

stand-up paddle boarding on Lizard Island

Go stand-up paddleboarding on the serene waters. (Image: Lizard Island)

Home to almost 1,000 islands in total, the Great Barrier Reef is where you’ll find the likes of Hamilton Island, Lizard Island, Lady Elliot Island and other highly coveted holiday hot spots. No matter where you point your compass, powdery white sand, rippling turquoise waters and outstanding snorkelling and diving hot spots abound.

9. You can spend a night under its waters

a family staying with the fishes at Reefsuites, Great Barrier Reef facts

Sleep with the fishes in Australia’s first underwater hotel. (Image: Tourism and Events Queensland)

Embrace responsible tourism throughout the Great Barrier Reef via environmentally friendly accommodation picks. Arguably the most unique is Australia’s first underwater hotel, Reefsuites. Guests are invited to lie in bed and watch as incredible marine life flutters beyond floor-to-ceiling windows. Two room styles are available — either a king double or twin single variety — and all meals are included in every stay.

an aerial view of Heart Reef, Great Barrier Reef facts

Glimpse the heart-shaped reef from above. (Image: Tourism and Events Queensland)

One of the best day trips departing off Hamilton Island, Heart Reef is a tiny cluster of coral that has created the shape of a heart, especially when viewed from above. Simple to snap while exploring the Great Barrier Reef through one of its best aerial-based tours (more on touring the Great Barrier Reef below), the highly Instagrammable attraction is located within Hardy Reef, less than 10 kilometres from the Reefworld pontoon, which houses the glorious Reefsuites.

11. Cairns and Port Douglas offer easy day trip access

Four Mile Beach, Port Douglas from above

The mountains meet the sea on Four Mile Beach. (Image: Tourism and Events Queensland)

Serving as the main ports for Great Barrier Reef day tripping, Cairns and Port Douglas are magnets for active holiday makers. The most responsible way to comb through the highlights is via one of the reef’s most environmentally conscious tours, blending first-hand insight (often from marine biologists) with expert navigation throughout the region’s ultra-vibrant sights.

12. Visitors can help cement a sustainable future

Great Barrier Reef boat tours on the turquoise, clear waters of Lady Musgrave Island

Sign up for environmentally conscious Great Barrier Reef tours. (Image: Tourism Australia)

There’s plenty more work to be done in ensuring the Great Barrier Reef remains as spectacular as it stands today. Play your part by choosing eco-conscious tours, which also support sustainable tourism, steering clear of physically touching coral, opting for mineral sunscreen rather than chemical-based varieties and removing litter where you can. They’re simple gestures but don’t underestimate their impact — our most beautiful natural creation requires more than a sliver of our attention.

Discover the best Great Barrier Reef accommodation near the Great Barrier Reef

Kristie Lau-Adams is a Gold Coast-based freelance writer after working as a journalist and editorial director for almost 20 years across Australia's best-known media brands including The Sun-Herald, WHO and Woman's Day. She has spent significant time exploring the world with highlights including trekking Japan’s life-changing Kumano Kodo Pilgrimage and ziplining 140 metres above the vines of Mexico’s Puerto Villarta. She loves exploring her own backyard (quite literally, with her two young children who love bugs), but can also be found stalking remote corners globally for outstanding chilli margaritas and soul-stirring cultural experiences.
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This Great Barrier Reef tour is the best thing I’ve done in Australia

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Evegreen Editor Rachael Thompson travelled to the world’s largest coral reef system for a once-in-a-lifetime experience.

I recently headed up to Hamilton Island to stay at the island’s newest resort, The Sundays. What I thought couldn’t be a more perfect couple of days exploring the luxury accommodation and Whitsunday Island became an even more incredible adventure after I was also invited to jump on a helicopter for the Journey to the Heart Tour to see Heart Reef.

The adventure began on Hamilton Island. Only six people can do this experience at any given time, so we hopped in a helicopter, ready to be treated to spectacular Whitsunday views. After about 30 minutes of flying, seeing Hamilton Island and the pristine Whitehaven Beach from above, we reached the striking boundary where the reef begins, with turquoise waters and clusters of coral coming into view.

A view of Whitehaven beach from a helicopter.

Aerial views of Whitehaven Beach. (Image: Rachael Thompson)

Eventually, the pilot informed us that we were about to fly around the Heart Reef. Heart Reef was discovered in 1975 by a local pilot. This exquisite natural phenomenon is approximately 17 metres long and, as the name suggests, is shaped like a heart. I’d seen photos of Heart Reef before, on postcards and marketing campaigns. But nothing compares to witnessing its distinctive shape in person. It’s the kind of moment that makes you pause not just to take a photo, but to truly take it in.

We circled above Heart Reef a couple of times to take in the full view before landing on a luxurious, sustainably designed pontoon in a nearby lagoon — the whole experience felt very James Bond-esque.

Aerial view of Heart Reef

Heart Reef from above. (Image: Jason Hill and Tourism & Events Queensland)

We headed downstairs, where there were tables and lounges for relaxing and taking in the idyllic views. Paddi, our friendly tour guide, greeted us and ushered us onto a small boat. Paddi drove us around the surrounding reef (you can’t get too close to Heart Reef), educating us on the species living in the area. It was here that I noticed myself feeling like my child-like self who visited the reef with my family when I was 10 years old. As Paddi pointed out colourful fish and coral through the boat’s glass bottom, I found myself gasping and exclaiming, “Look how cute it is!” I felt incredibly excited and lucky to witness the workings of one of the world’s greatest natural wonders.

A pontoon sitting on the Great Barrier reef near Heart Reef.

Your tour guide will take you on a boat around the reef. (Image: Tourism and Events Queensland)

We then headed back to the pontoon to get our snorkelling equipment and enjoy approximately 45 minutes in the water. Visitors are unable to snorkel or dive at Heart Reef due to its protected status, but the surrounding reef area is truly spectacular.

At a delightful 26.6 degrees Celsius, the water felt perfect. Parrotfish, Blue Stripe Clarkii Clownfish and needlefish playfully swam around, a large piece of coral proudly showed us its vibrant purple colour and giant clams rested serenely on the sandy seabed. With only six of us snorkelling, it was quiet and the energy was peaceful. 

A pontoon with a helicopter in the Great Barrier Reef.

Swim in pristine water and discover a myriad of marine species. (Image: Rachael Thompson)

To top off the experience, once we had finished snorkelling, we were treated to a glass of bubbles back on the pontoon, where we exchanged stories of how incredible the experience had been for each of us. 

It’s worth noting that there are no restroom facilities on the pontoon. As the excursion lasts approximately three hours, it’s advisable to plan accordingly before departure.

A view from a pontoon on the Great Barrier Reef.

Relax and enjoy a glass of bubbles while you admire the azure waters. (Image: Rachael Thompson)

At $1400 per person, this tour is definitely on the pricier end. But to be honest, it felt like a billionaire experience. Moments like this make me fall in love with Australia all over again and highlight even more how desperately this iconic part of the world needs to be protected.

Discover more incredible Great Barrier Reef tours