Beyond the continental shelf lies the true frontier of diving in Australia. While the Great Barrier Reef is its most famous jewel, the ultimate liveaboard experience in Australia reaches further out into the deep, clear water of the remote Coral Sea. These expeditions reach untouched outer reefs and steeply dropping oceanic walls, far from any day boat, and deliver a genuine sense of discovery on a colossal scale.
Most liveaboards depart from Cairns or Port Douglas in Queensland. Shorter itineraries work the Ribbon Reefs, a chain of ten reefs running north along the outer edge of the Great Barrier Reef, home to Cod Hole, where enormous and famously curious potato cod meet divers on the sand, and Steve's Bommie, a single pinnacle so densely packed with life that most divers do it twice. Longer trips push east to the Coral Sea, where sites such as Osprey Reef, Bougainville Reef and Holmes Reef rise from more than 1,000 metres of open ocean. Visibility at Osprey Reef regularly exceeds 40 metres, and North Horn is one of the most reliable shark dives in the Pacific, with grey reef and whitetip sharks, silvertips and occasional hammerheads patrolling the amphitheatre.
Further south and west, Australia offers dives found nowhere else: the Yongala wreck off Townsville, widely rated among the best wrecks in the world for sheer fish density; Ningaloo Reef in Western Australia for whale sharks between March and July and humpbacks from August to October; and the temperate reefs of South Australia for sea lions, leafy sea dragons and cage diving with great whites at the Neptune Islands.
Water on the tropical east coast runs between 23 and 29 degrees Celsius, warmest from December to March and coolest in July and August, when a 5 mm suit is welcome. Visibility ranges from 12 to 30 metres inshore and far more offshore. The Coral Sea season peaks from August to January, with the dwarf minke whale aggregation on the Ribbon Reefs from June to July offering one of the few in-water encounters with baleen whales permitted anywhere in the world. Coral spawning, usually in November, is another calendar highlight.
Marine life is vast: more than 1,500 fish species, six of the world's seven sea turtle species, manta rays, giant clams, nudibranchs in extraordinary variety and reef systems visible from orbit. Australian operators run to strict safety and environmental standards, and most vessels are large, stable and well-equipped for multi-day offshore crossings, with nitrox, camera stations and four to five dives a day including night dives.
Australia suits divers who want scale, structure and big animals in one trip. Reef dives are accessible to Open Water divers, while Coral Sea walls and shark dives are best enjoyed with an Advanced certification and comfort in blue water.
