The geography of the roughly T-shaped island is dominated by three features: two bays and a lagoon. More than half of the west coast of Chatham is taken up by the deep indentation of Petre Bay. The island's main settlement of
Waitangi is located in a small indentation in
Petre Bay's southern coast. Other significant settlements are
Kaingaroa on the northeast promontory and
Ōwenga on the south side of Hanson Bay. On the east coast is the larger
Hanson Bay, which stretches the full length of the island (). Much of the area between the bays is taken up by the large
Te Whanga Lagoon, which drains to the sea to the east, into the southern half of Hanson Bay. This lagoon covers about , and drains several small rivers that rise in the hills at the south end of the island. The next largest lakes are
Rangitahi and
Huro, northeast and southwest of Te Whanga. The central and north part of Chatham Island are mostly flat, with altitudes ranging from a few metres on the northeast and centre to 50 m on the northwest, but with a few scattered hillocks. The south part is higher, generally sloping down towards north and west; about half of it is over 150 m above sea level. The south coast of the island is mostly cliffs 100 m high or more. The highest point of the island (299 m) lies close to its southernmost point. s in north Chatham from 109m Tawirikoko to 99m Puhina, 134m Hemokawa, 151m Hokopoi, 125m Motuariki Hill, 149m Rangitihi, 188m Mt Chudleigh and 178m Korako. ==Climate==