The volcanic sea arch at Motukokako — known to most visitors as Piercy Island — was carved by millennia of wave action into a passage 18 metres wide and 15 metres high at mean tide. Māori oral tradition records the island as a waka shelter, its lee waters offering refuge during east-coast storms.
European surveyors charted the feature in 1769 during Cook's first Pacific voyage, though the opening was judged too narrow for naval transit. Today the hole in the rock cruise bay of islands departs Paihia Wharf hourly between 0730 and 1400, threading the arch only when sea swell remains below 1.5 metres and wind speed drops beneath 25 knots — conditions met on roughly 200 days per year.
The 144 islands scattered across the bay form New Zealand's densest marine reserve cluster. Bottlenose dolphins patrol the eastern channels year-round, their pods numbering between 80 and 120 individuals. Fur seals occupy the western rocks from May through October. The cruise route passes Roberton Island, where Captain Cook anchored in November 1769 to replenish water casks, and Moturua Island, site of a Department of Conservation revegetation program that has returned 300,000 native saplings to cleared pasture since 2001.
Catamarans operated under Department of Conservation permits hold between 60 and 150 passengers. Twin-hulled vessels draw less than two metres, enabling landings on sand beaches inaccessible to deeper-draft craft. Island stopovers last 30 to 45 minutes, sufficient time to walk the coastal bush tracks or wade the shallows. The hole in the rock cruise bay of islands tour spans three to five hours depending on route; longer sailings add a second island or extend into outer reef waters where orca sightings peak between January and March. All operators maintain real-time radio contact with the Paihia harbour master, who issues daily sea-state advisories at 0600. When conditions prevent passage through the arch, vessels circle the seaward face and return via the sheltered channel — the reef geology and marine life remain the same, only the framing shifts.
4 hr 30 min
