Great Barrier Reef

About Great Barrier Reef

Stretching for **2,300 kilometres along the northeastern coast of Australia** — from the tip of Cape York Peninsula in the north to Bundaberg in the south — the Great Barrier Reef is **the largest living structure on Earth, and the only one visible from space**. It is not a single reef but a system of **almost 3,000 individual reefs and 900 islands**, home to a biodiversity that rivals any ecosystem on the planet: **over 1,500 species of fish, 4,000 species of mollusc, 240 species of birds, 30 species of whales and dolphins, six of the world's seven species of marine turtles, and more than 600 species of coral**. The reef system has been building for **approximately 500,000 years on the accumulated remains of countless generations of coral polyps** — tiny animals that extract calcium carbonate from the sea to build their limestone skeletons. The Great Barrier Reef was **inscribed as a UNESCO World Heritage Site in 1981**, described at the time as one of the most remarkable ecosystems on the planet. That description remains accurate — and so does the warning that followed: **the reef is under severe and accelerating threat**. Rising ocean temperatures caused by climate change trigger **coral bleaching events, in which stressed corals expel the algae that give them colour and energy**. The reef experienced **five mass bleaching events between 1998 and 2022, with the 2016 and 2017 events killing approximately 50% of the shallow-water coral in the northern sections**. Scientists describe the reef as in crisis; its long-term survival depends almost entirely on whether global greenhouse gas emissions are brought under control within the next decade. The main gateway to the reef is **Cairns, a city in Far North Queensland with an international airport and excellent reef access**. Day trips to the outer reef — where coral quality and visibility are generally best — depart daily from Cairns and Port Douglas. **Snorkelling is rewarding for beginners; scuba diving opens a deeper world of caves, walls, and nocturnal life**. The **Whitsunday Islands, further south, offer a different experience: sailing between islands fringed by coral and white sand, with Whitehaven Beach among the most beautiful in the world**. The best time to visit is **from June to October, during the dry season**, when conditions are clearest. Avoid November to May when jellyfish are more prevalent and the wet season reduces visibility.

Highlights

• ✦ World's largest coral reef system, 2,300 km long
• ✦ Home to 1,500 species of fish and 400 types of coral
• ✦ Visible from space; a UNESCO World Heritage Site

Practical info

Frequently asked questions

How much does a Great Barrier Reef day trip cost?

A standard snorkelling or diving day trip from Cairns or Port Douglas costs from around €135 per person, including equipment, lunch and a marine park fee that is usually added separately. Pontoon-based tours with extras such as a semi-submersible or helicopter add-on cost considerably more. Prices vary by operator, boat size and how far offshore the reef site is.

Which town is the better base, Cairns or Port Douglas?

Cairns has the international airport and the widest choice of boat operators and price points, while Port Doutdouas sits closer to some of the outer reef's better-regarded sites and has a quieter, more upmarket feel. Many visitors fly into Cairns and either stay there or transfer about an hour up the coast to Port Douglas by shuttle bus. Both towns run comparable day-boat schedules to the reef.

Do you need to know how to swim or dive to visit the reef?

No, most day-boat operators offer snorkelling with flotation vests and platforms for non-swimmers, plus semi-submersible or glass-bottom boat viewing for those who prefer to stay dry. Introductory scuba dives with an instructor are widely available for certified and uncertified visitors alike. Life jackets and safety briefings are standard on every trip.

What is the best time of year to visit the Great Barrier Reef?

June to October generally offers the clearest water, lower humidity and calmer seas, making it the most popular window for reef trips. Stinger (jellyfish) season from around November to May in northern Queensland means full-body lycra suits are worn while swimming, which operators provide free of charge. Cyclone risk is highest from December to March, which can occasionally disrupt boat schedules.

How much of the Great Barrier Reef has been affected by coral bleaching?

Repeated marine heatwaves since 2016 have caused mass bleaching events across large sections of the reef, though the reef spans over 2,300 km and impact varies significantly by location, with some areas showing strong recovery and others more damage. Marine park fees paid by visitors fund reef monitoring and restoration research. Choosing operators certified under Ecotourism Australia's high-standard programs supports lower-impact visits.

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