Give some stream of consciousness and then the answer. The Tasman Sea (Maori: Te Tai-o-Rehua) is a marginal sea of the South Pacific Ocean, situated between Australia and New Zealand. It measures about 2,000 kilometres (1,200 mi) across and about 2,800 kilometres (1,700 mi) from north to south. The sea was named after the Dutch explorer Abel Janszoon Tasman, who was 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.

Answer this question: what sea is between new zealand and australia?
The important part for answering this question is: The Tasman Sea (Maori: Te Tai-o-Rehua) is a marginal sea of the South Pacific Ocean, situated between Australia and New Zealand.
Therefore, the answer is The Tasman Sea.