Doubtful Sound / Patea

Doubtful Sound / Patea is a fiord in Fiordland, in the far south west of New Zealand. It is located in the same region as the smaller but more famous and accessible Milford Sound / Piopiotahi. It took second place after Milford Sound as New Zealand's most famous tourism destination.

At 40 kilometres (25 mi) long, Doubtful Sound / Patea is the second longest, and with a depth of up to 421 metres (1,381 ft) the deepest of the South Island's fiords. In comparison with Milford Sound, it is more widespread, with the cliffs not as dramatically tall and near vertical. However, the U-shaped profile of the fiord is obvious, in particular on the two innermost of the main fiord's arms and the hanging side valleys along the main fiord.

Like most of Fiordland, Doubtful Sound receives a high amount of rainfall, ranging from an annual average of 3,000–6,000 millimetres (120–240 in). The vegetation on the mountainous landscape surrounding the fiord is dense native rainforest.

Doubtful Sound was named 'Doubtful Harbour' in 1770 by Captain Cook, who did not enter the inlet as he was uncertain whether it was navigable under sail. It was later renamed Doubtful Sound by whalers and sealers, although it is not technically a sound but a fiord.

A Spanish scientific expedition commanded by Alessandro Malaspina visited Doubtful Sound in February 1793 to conduct experiments measuring the force of gravity using a pendulum, a part of the effort to establish a new metric system. The officers of the expedition, which included Felipe Bauzá y Cañas, a cartographer, also made the first chart of the entrance and lower parts of the Sound, naming features of it. Today these form a unique cluster containing most of the Spanish names on the map of New Zealand: Febrero Point, Bauza Island and the Nee Islets, Pendulo Reach, and Malaspina Reach.

Following the passage of the Ngāi Tahu Claims Settlement Act 1998, the name of the fiord was officially altered to Doubtful Sound / Patea.

Doubtful Sound lies deep within the Fiordland National Park, about 50 kilometres (31 mi) from the nearest inhabited place, the small town of Manapouri, and is surrounded by mountainous terrain with peaks typically reaching 1,300–1,600 metres (4,300–5,200 ft). Along the coast, there are no settlements for about 200 kilometres (120 mi) in either direction.

There are three distinct arms to the sound, which all extend to the south from the main fiord. From the major conflux of water just south of Secretary Island, these arms are: