"Archaeologists recreate ancient voyage: 200km canoe trip from Taiwan to Japan tests human endurance"

Dr. Yousuke Kaifu was conducting research at an archaeological site on Japan’s Okinawa islands when a question began to form in his mind. The artifacts unearthed during the dig suggested humans had lived there 30,000 years ago, arriving from both the north and the south. Yet, the methods of their journey remained unclear.

"While we found stone tools and other remains, they don't explain how these people crossed the water," said Kaifu, an evolutionary anthropologist at the University of Tokyo.

During the Paleolithic era, technology was primitive. "It’s remarkable that they reached these islands with such basic tools. I wanted to understand how," he said.

This curiosity led Kaifu to develop an experimental project: a 225-kilometer canoe voyage from Taiwan to Yonaguni, the westernmost of Japan’s Ryukyu Islands. Despite being the shortest crossing among the Ryukyus, the route passes through one of the world’s strongest ocean currents. The expedition echoed Thor Heyerdahl’s famed 1947 Kon-Tiki journey, which demonstrated that ancient South American peoples could have traveled to Polynesia by raft.

First, the team needed a suitable vessel. Since no Paleolithic boats survived, they constructed rafts using traditional materials like bamboo and reeds. Initial tests, however, showed these were too slow to withstand the powerful Kuroshio Current, which would have been even stronger in ancient times.

"Those attempts taught us how difficult the crossing was. Yet, we knew Paleolithic people had made it, so there had to be a way we just hadn’t discovered yet," Kaifu explained.

After further experimentation, they built a heavy but functional dugout canoe from Japanese cedar and chose Wushibi Bay on Taiwan’s east coast as their departure point.

Yonaguni is not visible from Taiwan’s shoreline but can be glimpsed from high ground near Taroko on clear days. Researchers hypothesized that early migrants had likely seen the island and understood the Kuroshio’s patterns from fishing experience.

The five-person crew included scientists and experienced paddlers, though none had attempted such a voyage without modern navigation. On departure day, rough seas and overcast skies obscured the stars they had planned to guide them, forcing the team to rely on an old technique—reading the ocean’s swells to maintain direction.

"Polynesian and Micronesian navigators used this method—we learned it from them," said Kaifu, who observed from a support boat, which he jokingly called "the safe place."

For 45 hours, the crew endured exhaustion, muscle pain, and hallucinations. "Surrounded only by sea and sky, they were unsure if they were making progress," Kaifu recalled.