Uninhabited since the 1820s, they are a nature reserve and popular underwater diving spot, with boat tours typically departing from Tutukaka.

The Poor Knights Islands are the eroded remnants of a 4-million-year-old rhyolitic volcano that is estimated to have been 1,000 metres (3,300 ft) tall and 25 kilometres (16 mi) in diameter.

These are a form of internal wave driven by the local tidal flow forcing the stratification against sloping areas of the shelf face.

[6] The Poor Knights Islands were created in some of the earliest eruptions of the Coromandel Volcanic Zone, between 10 and 9.5 million years ago.

The Poor Knights Islands vulcanism represents an early period for the Coromandel Volcanic Zone, as changes in tectonic forces caused the east belt of the Northland Arc (23 to 16 million years ago) to begin moving southwards, and eventually forming the modern Taupō Volcanic Zone.

[8] The islands have been identified as an Important Bird Area, by BirdLife International because they are home to a breeding population of about 200,000 pairs of Buller's shearwaters.

[12] The islands were earlier inhabited by Māori of the Ngāti Wai and Ngati-Toki tribes who grew crops and fished the surrounding sea.

As Waikato had been offended by Tatua some years previous when he was refused pigs he had come to trade for, so he and his warriors set out on three large canoes to attack the islands.