A map linking all of northern Queensland's coastal ports and offshore resorts from the Whitsundays north to Lizard Island would look like a lace-up boot 1,600 km (1,000 miles) long. However, you'd only see less than half the reef, which extends south to Lady Elliot Island and as far north as the near-roadless wilderness of Cape York and the shores of Papua New Guinea.

If you're visiting the reef only briefly, it's simplest and most economical to day-trip from the mainland. Some reef-island resorts are accessible by boat; others can be reached only by plane, and both airfare and lodging rates can be expensive. Day trips depart from major coastal cities including Cairns, Port Douglas, Townsville, and Airlie Beach. Some island resorts, such as Hamilton, let you visit and use their facilities for the day—then return you to the mainland.