Chatham Island is by far the largest island of the Chatham Islands group, in the south Pacific Ocean off the eastern coast of New Zealand. It is said to be «halfway between the equator and the pole, and right on the International Date Line». The island is called Rekohu («misty skies») in Moriori, and Wharekauri in Maori.
The island was named after the survey ship HMS Chatham which was the first European ship to locate the island in 1791. It covers an area of 920 square kilometres (355 sq mi). Chatham Island lies 650 km (404 mi) south-east of Cape Turnagain, the nearest point of mainland New Zealand to the island.