The Bay is aptly named, with six large, and around 140 small, islands. Many are subject to the DOC-led Project Island Song, which aims to rid many islands of introduced predators and turn them into wildlife havens. Assorted birds have been reintroduced to many islands, notably Urupukapuka Island, which can be explored in a few hours using DOC’s Urupukapuka Island Archeological Walk leaflet highlighting Maori pa and terrace sites.
Of the other large islands, by far the most popular is Motuarohia (Roberton Island), where DOC manages the most dramatic central section, an isthmus almost severed by a pair of perfectly circular blue lagoons. Snorkellers can explore an undersea nature trail waymarked by inscribed stainless-steel plaques.
Other sights that often feature on cruise itineraries include the Black Rocks, bare islets formed from columnar-jointed basalt – these rise only 10m out of the water but plummet a sheer 30m beneath. At the outer limit of the bay is the craggy peninsula of Cape Brett, named by Cook in 1769 after the then Lord of the Admiralty, Lord Piercy Brett. Cruises also regularly pass through the Hole in the Rock, a natural tunnel through Piercy Island, which is even more exciting when there’s a swell running.