Doubtful Sound / Patea

Doubtful Sound / Patea is one of the grandest of the fiords that cut into the south-western edge of New Zealand's South Island: about 40 km long, up to 2 km wide and as much as 421 metres deep, it is the second longest and the deepest of them. It owes its English name to James Cook, who sailed past in 1770 and, unsure whether he could get his ship back out against the wind, called it "Doubtful Harbour"; sealers and whalers later made it a sound. A Spanish expedition in 1793 left names still on the map — Malaspina Reach, Bauza Island, Febrero Point — and since 1998 the fiord officially carries its Māori name Patea as well.

The main channel branches into three arms, Crooked Arm, Hall Arm and First Arm, walled by mountains that plunge straight into the water and are clothed in dense rainforest. Rain falls heavily here, three to six metres a year, and after a downpour hundreds of temporary waterfalls stream down the cliffs. So much fresh water pours in that it floats in a distinct, low-salinity layer on top of the sea water below; the lack of light lets black coral grow at unusually shallow depths. The fiord is also home to a resident group of bottlenose dolphins, New Zealand fur seals, and Fiordland penguins that breed on its shores.

What visitors remember most is the scale and the quiet. Far from any road network, with no town on its shores, the sound is so still on calm days that the walls reflect perfectly in the water; the silence is part of the experience. Towards the open sea the fiord widens past Secretary Island and the Shelter Islands to the Tasman. Even the one industrial trace — the tailrace of the Manapouri underground power station emptying into Deep Cove — is hidden inside the mountain.

Getting there

The fiord lies within Fiordland National Park, about 155 km in a straight line from Invercargill, whose airport (IVC) is the nearest with scheduled flights; in practice visits start from the village of Manapouri, about 20 minutes' drive from Te Anau and roughly two hours by road from Queenstown. Boats cross Lake Manapouri to its West Arm, a coach then crosses the 671-metre Wilmot Pass on a gravel road unconnected to the national network, and cruises depart from the wharf at Deep Cove. Day and overnight trips include all transport.