BLOG 7: What were the wind and current challenges faced by the first Polynesian voyages to New Zealand?

Waka in Storm

There are three major considerations when navigating long distances in a sailboat or canoe/waka from a Pacific Island across the Pacific Ocean to arrive in New Zealand or departing from New Zealand for a Pacific Island destination: wind direction, ocean currents and the method of navigation.These physical factors defined the experience for New Zealand's first settlers and shaped New Zealand's origin story.

Winds

In the Southern Hemisphere winds blow in an anti-clockwise direction. Two bands of winds are relevant: the Trade Winds near the Equator and Westerlies further south. The Trade Winds blow from the south-east and easterly closer to the Equator. From the Equator the winds head south westerly until the Westerly band is reached where the winds blow in an easterly direction. These patterns were essential for the success of Polynesian Migration to New Zealand.

With a following wind, a double-hulled, sail-equipped waka could journey from Polynesia in the general direction of Australia and New Zealand. This route would have been far more arduous than for any Southeast Asian Migration to New Zealand due to the absence of any land masses enroute.

The Roaring Forties are areas between latitudes 40° and 50° south in the Southern Hemisphere, where the prevailing winds blow persistently from the west. The roaring forties have strong, often gale-force, winds throughout the year. The 40 degrees latitude line passes through Wanganui with the 50 degrees latitude line passing just north of the Auckland Islands.

Navigating long ocean voyages in wakas through the Roaring Forties would have exposed sailors to extreme danger, a reality even for the legendary Kupe.

South Pacific Surface Currents. The currents are driven by the wind.

Currents

New Zealand is bathed from the west by three major water masses. The boundaries of these masses are called fronts. These are the Tasman Front (TF), Subtropical Front (STF) and Subantarctic Front (SAF). The Tasman and Subtropical fronts are relatively warm surface currents. The eastward flow of warm water splits around the country so that currents flow south-eastwards around the North Island’s east coast, and north-westward around the South Island’s east coast.

What are the implications of currents and winds for navigation across oceans?

To travel from a Pacific Island to New Zealand, a sailboat or canoe (waka) would first need to depart toward the east coast of Australia. This route allows the vessel to take advantage of south‑westerly winds. As the journey progressed, the boat would then be carried by the Westerlies and the Tasman Front current across the Tasman Sea to New Zealand.

Traditional Polynesian Canoe Sail Configuration

For the return journey to a Pacific Island, the vessel would initially be driven eastward by the Westerlies toward South America, where it would encounter northerly currents flowing along the South American coastline. Eventually, the boat would reach the easterly Trade Wind belt, enabling a westward passage back to a Pacific Island. As previously discussed, it is highly improbable that any waka ever took this route.