The Tasman Sea is the large body of water between Australia and New Zealand, some 2000 kilometres (1250 miles) across. It is a south-western segment of the South Pacific Ocean. The sea was named after the Dutch explorer Abel Janszoon Tasman, the first recorded European to encounter New Zealand and Tasmania. The British explorer Captain James Cook later extensively navigated the Tasman Sea in the 1770s as part of his first voyage of exploration.
The Tasman Sea is deemed by the International Hydrographic Organisation to include the waters to the east of the Australian states New South Wales, Victoria and Tasmania. The northern state of Queensland neighbours the Coral Sea, and the boundary between New South Wales and Queensland is also used as the boundary between the two seas.
The Tasman Sea had a mid-ocean ridge about 85-55 million years ago as Australia and Zealandia broke apart during the breakup of supercontinent Gondwana.
The Tasman Sea features a number of mid-sea island groups, quite apart from coastal islands located near the Australian and New Zealand mainlands:
These island groups are each Australian possessions.
The Tasman Sea is nicknamed The Ditch, eg crossing the ditch means going to Australia from New Zealand or vice versa.