The 18-metre natural arch that punctures Motukokako Island was carved by millennia of storm surge and tidal abrasion, its basalt walls smoothed to a glossy black patina by the Pacific.
Māori navigators called the passage Te Moko Tapu, the sacred gateway, and used it as a sighting point for seasonal voyages between the outer islands and the mainland bays. European whalers mapped it as Piercy Island in 1820, naming the formation for the stark daylight visible through the bore, and by the 1870s coastal traders were threading schooners through the arch on calm-water days as a test of nerve and seamanship.
Today the hole in the rock cruise paihia departs from Paihia's Maritime Building on Marsden Road, where twin-hulled catamarans and enclosed touring vessels queue along the timber wharf each morning. The voyage traces the eastern coastline of the Bay of Islands, passing Tapeka Point and the forested slopes of Roberton Island before rounding Cape Brett's granite headland. Bottlenose dolphins shadow the vessels in austral spring and summer, breaching in the bow wake as the fleet crosses the 12-kilometre open-water stretch between the inner bay and Motukokako. The arch itself measures 15 metres at high tide, narrowing to 12 at the spring ebb, and captains time the passage to coincide with slack water when the swell drops below one metre.
The island's volcanic origin is legible in the columnar jointing of the basalt and the rust-coloured oxidation streaks that run vertically down the exterior face. Terns and shags nest on the western cliffs, and the surrounding reef drops to 40 metres within 200 metres of the shore, creating upwelling currents that draw pelagic fish and, occasionally, orca pods. The cruise route extends beyond Motukokako to the outer islands of the Cavalli group on longer itineraries, returning via the sheltered channel between Moturua and Urupukapuka, where passengers disembark for a timed island stopover. The entire circuit covers between 40 and 60 nautical miles depending on the vessel and sea state, with departure frequency highest between October and April when the Tasman swells subside and visibility exceeds 15 kilometres. Modern hole in the rock cruise paihia tours carry hydrophones for real-time cetacean tracking and deploy polarised viewing ports below the waterline, allowing passengers to observe the reef structure without surface glare.
4 hr 30 min
