Coral Sea

Off the northeastern shoulder of Australia lies the Coral Sea, a vast, warm expanse of the South Pacific named for the living wonder along its western edge — the Great Barrier Reef, the largest structure ever built by living organisms. Beyond the reef the sea opens into a deep, island-flecked blue that stretches toward Vanuatu and New Caledonia. It was also the scene, in 1942, of one of the great turning points of the Pacific War, the first naval battle in history fought entirely beyond the sight of the opposing fleets.

Covering some 4.79 million square kilometres, the Coral Sea is one of the largest seas on Earth, deepening from the Australian shelf into basins that plunge to about 9,140 metres. Warm tropical water and the absence of major rivers keep it clear and nutrient-poor — ideal conditions for coral — and along its western rim the Great Barrier Reef stretches more than 2,000 kilometres. Scattered atolls and submerged reefs dot its open waters, and the warm currents that flow through it help drive the climate of eastern Australia.

Long known to the seafaring peoples of Melanesia and to the Aboriginal nations of the Queensland coast, the sea entered Western awareness when James Cook nearly wrecked the Endeavour on its reefs in 1770. The 1942 Battle of the Coral Sea blunted Japan's advance toward Australia and showed the world the power of carrier aviation. Today the sea is the focus of vast marine conservation efforts, including one of the world's largest marine parks, as warming waters and repeated bleaching events threaten its defining reef.

• Tasman Sea
  The stormy stretch of ocean dividing Australia and New Zealand adjacent to
• Great Barrier Reef
  The largest living structure on Earth, a 2,300-kilometre coral system off Australia contains
• Pacific Ocean
  Earth's largest and deepest ocean drains to
• Oceania
  The smallest continent, built around Australia and the Pacific isles located on