The Raft Kon-Tiki

On the morning of 28 April 1947, a tugboat towed a strange craft out of the harbour of Callao, in Peru, and left it bobbing on the open Pacific.

It was a raft made of nine thick logs of balsa wood, tied together with rope. It had a small cabin of bamboo with a roof of banana leaves, and a square sail with a painted face on it.

Six men stood on board, and a green parrot. Ahead of them lay about seven thousand kilometres of ocean.

A bold idea

The leader was a young Norwegian named Thor Heyerdahl. Before the Second World War he had lived for a year on Fatu Hiva, one of the Marquesas Islands in Polynesia, in the middle of the Pacific Ocean.

There, he began to wonder how people had first reached these islands, so far from any continent. Most scholars believed the Polynesians had come from Asia, sailing east. Heyerdahl had a different idea. He noticed that the winds and currents in that part of the ocean flow from east to west, from South America towards Polynesia. Could ancient people from South America have drifted across on rafts?

The experts were not convinced. A balsa raft, they told him, would soak up water and sink long before it reached Polynesia.

So Heyerdahl decided to find out for himself.

Building the raft

He went to Ecuador, travelled into the forest, and had large balsa trees cut down. The logs were floated down a river to the coast, then shipped to Peru.

In the naval harbour at Callao, Heyerdahl and his crew built the raft as closely as they could to the old designs they had read about. They used no nails, no wire and no metal at all. Everything was lashed together with hemp rope. They named the raft Kon-Tiki, after a sun god in old Peruvian legends.

The crew were Heyerdahl and four other Norwegians, Herman Watzinger, Erik Hesselberg, Knut Haugland and Torstein Raaby, and a Swede, Bengt Danielsson, who spoke Spanish. Haugland and Raaby were radio operators, and they brought a small radio to send reports of their progress.

Life on the ocean

Once the trade winds caught the sail, the Kon-Tiki moved steadily west. The crew took turns at the steering oar, day and night.

The ocean was full of life. Every morning they found flying fish that had landed on the deck in the night, and fried them for breakfast. Dolphins and tuna swam around the raft. Once, an enormous whale shark, the biggest fish in the sea, circled the raft for a long time, swimming underneath it, before slowly going away.

The balsa logs did soak up some water, just as the experts had warned. But they did not sink. The ropes bit into the soft wood and stayed tight, rather than wearing through.

There were frightening moments. Storms drenched the cabin and tossed the raft about. One day, Watzinger fell overboard, and the raft drifted away from him faster than he could swim. Haugland dived in with a lifeline and swam to him, and the others hauled them both back aboard.

The reef

After more than three months at sea, the crew finally saw land: a small island in Polynesia. But the currents carried them past it.

On 7 August 1947, the 101st day of the voyage, the Kon-Tiki was swept onto a coral reef at Raroia, in the Tuamotu Islands. Huge waves smashed over the raft. The crew clung to the logs as the surf pounded them across the reef. The cabin was crushed and the mast broke.

But the balsa logs held together. When the sea calmed, all six men waded across a lagoon to a small, uninhabited island with palm trees. They were bruised, but alive. A few days later, people from a nearby village paddled over in canoes to see who had arrived.

What it proved

The voyage of the Kon-Tiki showed that a simple raft could cross thousands of kilometres of the Pacific. Heyerdahl's book about the journey sold millions of copies around the world, and his film of the voyage won an Academy Award.

Most scientists today still believe that the Polynesians came mainly from the west, from Asia, as skilled sailors who navigated on purpose, not by drifting. But recent research suggests that Polynesians and South Americans did meet at some point long ago. Heyerdahl was not entirely right. But he was not entirely wrong, either.

The Kon-Tiki raft itself can still be seen today, in a museum in Oslo, Norway.

Want to read more?

Thor Heyerdahl's own book, The Kon-Tiki Expedition, is a lively, funny and gripping account of the voyage. The Kon-Tiki Museum in Oslo displays the original raft.