Northern Arch – Poor Knights Islands Marine Reserve

Site Overview

Northern Arch at the Poor Knights Islands is the premier big-animal dive site in New Zealand, famous for its seasonal grey nurse shark encounters and dramatic underwater topography that creates a cathedral-like environment for both predators and prey. The massive archway spans the northern headland of the island group, with sheer walls dropping to 30 metres covered in the densest soft coral gardens found anywhere in the marine reserve. Grey nurse sharks, also known as sand tiger sharks, visit the Northern Arch from February to May, gliding gracefully through the archway and along the outer walls in one of the few places in the world where these prehistoric-looking sharks can be observed in their natural habitat. Bronze whaler sharks also patrol the deeper water beyond the reef, while huge kingfish and stingrays are resident throughout the year. The arch interior creates a spectacular silhouette effect with light streaming through from the opposite side, illuminating the thousands of pink maomao and sweep that fill the water column. The walls are draped in orange and purple soft corals, black coral fans, and colourful gorgonians that thrive in the nutrient-rich currents flowing through the channel. The combination of shark encounters, dramatic geology, and pristine marine reserve protection makes Northern Arch an essential destination for any serious diver visiting New Zealand.