This story appears in the July 2017 issue of National Geographic magazine.

Settling the islands of the Pacific Ocean was one of the greatest maritime adventures in human history. Some 3,400 years ago people began to sail from Southeast Asia, crossing hundreds of miles of open water to find specks of land where they could build new lives. Archaeological evidence provides a time line of when the individual islands were colonized. But scientists are uncertain about the precise starting points of the voyages and how the early sailors managed to travel such long distances.

A new study has worked out likely scenarios by combining computer simulations of seafaring with climatic and oceanographic data. Some colonists probably set out from the Moluccas in northern Indonesia, arriving in Palau, about 500 miles away. Others may have left the Bismarck Archipelago near New Guinea and ended up as far east as Samoa and Tonga.

Once people reached western Polynesia, their explorations stalled for the next two millennia. The study suggests why. Sailors started off with the wind at their backs, but near Samoa the wind reverses and they were stranded. Eventually they learned to sail against the wind, which allowed them to continue eastward.

“Going farther, to remote Oceania, required a very different voyaging strategy from what was used before,” says University of Oregon archaeologist Scott M. Fitzpatrick, who contributed to the research. “No islands were visible, so sailors had to use a celestial compass.”

They also developed the double-hulled voyaging canoe, which would carry them to Hawaii, Easter Island, and New Zealand on trips lasting up to two months. “Sailing so far was ambitious and dangerous and a challenging test of endurance,” says Fitzpatrick. “They were exceptional seafarers, no doubt about it.”

Early Island Culture