These islands stand at the entrance to Pelorus Sound, have a maximum height of 240 m, with rocky shores and little in the way of quiet, sheltered anchorages.
In N sector winds the south-east coast offers calm water but can be gusty with poor holding and is not recommended for overnight anchorage, except in light N sector winds.
Of the three bays on the south-east side of Nukuwaiata Island, the middle one provides the best shelter.
A shelf extends out from Nukuwaiata to the Haystack approximately half a mile to the south-east. About midway between the Haystack and Nukuwaiata is Pelorus Rock which is about 1 m below the surface at low water.
Considerable care should be exercised if navigating through this passage.
There is a passage between Nukuwaiata and Te Kakaho Island. This passage is not wide and care should be taken to stay approximately half way between Nukuwaiata and the islets of Te Kakaho Island.
A long dangerous reef of rocks extends nearly half a mile from the north-east end of Te Kakaho. These rocks are generally visible at all states of the tide but there is a rock approximately 20 m from the end of the reef that is covered by high water.
The Chetwodes are a wildlife sanctuary and landing is prohibited without a permit.
Nine Pin Rocks extend 550 m from the southern end of Nukuwaiata Island. These rocks and islands are up to 16 m in height. It is impossible to pass between the reef and the outer rock on which the lighthouse stands.
The area surrounding the rocks is foul ground, and drops sharply to 40 metres.
Hinemoa Rock is approximately 400 m from the western shore of Nukuwaiata Island. There is a clear passage between Hinemoa Rock and Nukuwaiata Island.
A transit of Stewart Island in Admiralty Bay and Clay Point leads clear to the north of the rock and Post Office Point off Ketu Bay in Pelorus Sound, open on the western extremity of Nukuwaiata, will lead onto the western side of the rock.
Similarly Blowhole Point, just open on the same western end of Nukuwaiata, will lead onto the eastern side of Hinemoa Rock.
The rock shown off the western end of Nukuwaiata is about 20 m from the shore and just below the surface at low water.