The Coral Sea borders the Great Barrier Reef on its eastern, ocean-facing side.
The reef runs along the northeastern coast of Queensland, while the Coral Sea extends eastward toward island nations and territories of the southwestern Pacific. The reef is therefore not in a lake or a completely enclosed coastal bay; it is part of a broad tropical marine system connected to the open ocean.
The Coral Sea also contains many reefs, islands and deep ocean basins beyond the Great Barrier Reef. Its waters influence currents, weather, marine life and the movement of species through the region.
A common mix-up is the Arafura Sea, which lies north of Australia between the continent and New Guinea. The Tasman Sea is farther south, between Australia and New Zealand, and does not border the Great Barrier Reef.