The Great Barrier Reef stretches roughly 2,300 kilometres along the Queensland coast and covers about 344,400 square kilometres — an area larger than Italy. It is made up of some 2,900 individual reefs and 900 islands, and it is the only living structure visible from space. UNESCO listed it in 1981.
What lives there
The numbers are hard to hold in the head: 1,625 species of fish, more than 600 types of coral, 133 species of sharks and rays, 30 species of whales and dolphins, and six of the world's seven marine turtle species. Dugongs graze the seagrass meadows in the shallows. On a single snorkelling stop over a healthy bommie you will typically see parrotfish, giant clams, wrasse and reef sharks that ignore you entirely.
The state of the coral — honestly
Mass bleaching events have hit the reef in 1998, 2002, 2016, 2017, 2020, 2022 and 2024. The 2016 event killed roughly 30 percent of shallow-water corals in the northern section. Bleaching happens when prolonged heat forces coral to expel the algae that feed and colour it; if the water cools in time the coral can recover, and much of it has. Outbreaks of crown-of-thorns starfish, which eat coral, are a second pressure and are actively culled.
None of this means the reef is gone. It means the healthiest coral is now further out and further south, and that operators who take you to outer-reef sites rather than the closest inshore ones are worth the extra hour on the boat.
Where to base yourself
- Cairns — the busiest hub, most operators, most competition on price. Outer reef in 90 minutes.
- Port Douglas — an hour north, quieter, closer to the Agincourt ribbon reefs, and next door to the Daintree rainforest.
- Airlie Beach / Whitsundays — 74 islands, sailing trips, and Whitehaven Beach, seven kilometres of sand that is 98 percent pure silica and stays cool underfoot.
- Lady Elliot Island — the southern tip, a coral cay reachable only by light aircraft; the best odds anywhere on the reef of swimming with manta rays.
Things worth knowing before you book
- Stinger season runs November to May. Box jellyfish and the tiny Irukandji are genuinely dangerous; operators supply full-body stinger suits and you should wear one.
- Heart Reef in the Whitsundays cannot be swum — it is protected and only viewable from a scenic flight.
- An Environmental Management Charge of a few dollars per day is added to every reef trip and goes to park management.
- Best visibility: the dry season, roughly June to October, when winds drop and the water clears.
- You do not need a diving licence — most operators run introductory dives with an instructor, and the snorkelling is excellent.