Doubtful Sound is not a sound at all. It is a glacier-carved fiord, roughly 40 kilometres long and 421 metres deep at its lowest point. James Cook charted the entrance in 1770 and declined to sail in, doubtful that wind could carry a ship out again. The name held. Māori had already called the water Patea, the place of silence. A Doubtful Sound Day Cruise from Manapouri still begins with that same reluctance of access, because the fiord is reached only by crossing a lake and then a mountain range. No road runs from the township to the coast. Passengers cross Lake Manapouri to West Arm, 20 kilometres of tannin-dark water hemmed by silver beech. The Wilmot Pass road climbs from there, 22 kilometres of gravel cut between 1963 and 1965 to haul turbine components to the Manapouri Power Station. It cost more per kilometre than any road built in New Zealand to that date. It serves no settlement, and every Doubtful Sound Day Cruise from Manapouri tour still depends on it. Heavy vehicles reach the pass only by barge. The fiord lies within Fiordland National Park, part of the Te Wāhipounamu UNESCO World Heritage Area. Close to six metres of rain falls here each year, and it returns as waterfalls down bare granite: Browne Falls, Helena Falls, and hundreds of unnamed threads that appear within an hour of a downpour. Rain and meltwater float three to four metres above the seawater, stained the colour of strong tea. That dim upper layer draws deep-water species into shallow habitat, and black coral colonies grow at ten metres where they would otherwise sit at a hundred. Bottlenose dolphins hold territory in Hall Arm. Fur seals haul out on the Nee Islets. Tawaki, the Fiordland crested penguin, nests under coastal scrub. None of this was assured. A 1970 proposal to raise the lake by up to 30 metres for hydro generation drew 265,000 signatures, then the largest petition in the country's history, and the scheme was abandoned in 1972. The wilderness cruises operating today move through the landscape that campaign preserved. Commander Peak rises almost vertically at the entrance to Hall Arm. Seal Rock and the Shelter Islands mark the open Tasman approach, where swell arrives unbroken from Australia. Doubtful Sound Day Cruise from Manapouri tours carry a few hundred visitors a day into a fiord that holds no permanent population, no shoreline settlement, and no road out.