A team of five paddlers will attempt to cross 200 kilometers of open ocean in a primitive log boat.

National Museum of Nature and Science/Tokyo

Explorers to voyage to Japan in primitive boat in hopes of unlocking an ancient mystery

By Dennis NormileJul. 2, 2019 , 3:05 PM

In the next week or so, five adventurers will attempt to paddle a primitive hand-hewn canoe across 200 kilometers of ocean in hopes of revealing how humans originally populated East China Sea islands. The 40-hour trip, from Taiwan to Yonaguni, the westernmost of Japan’s Okinawa Islands, is the culmination of a 6-year effort to experimentally determine what kinds of craft Paleolithic peoples may have built and used, and how they navigated over long ocean voyages.

Archeological sites show humans first arrived in Japan more than 30,000 years ago. They likely reached the main islands from northeast Asia via a land bridge from Siberia and by crossing the straits in watercraft from the Korean Peninsula.

But how Paleolithic humans settled the Ryukyus, the present-day Okinawa Islands that stretch 1200 kilometers from Taiwan to Japan's Kyushu Island, “is really a big mystery,” says Yousuke Kaifu, an archaeologist at Japan's National Museum of Nature and Science in Tokyo who dreamed up the expedition. The “very difficult” sea voyages were undoubtedly made in boats built of materials that have not survived, he says. And sailing boats had not yet appeared, So Kaifu’s team has been building and testing watercraft that prehistoric seafarers might have paddled.

Yonaguni can be seen from Taroko Mountain in northeastern Taiwan. So ancient peoples presumably knew of the island, even though it can’t be seen from shore, Kaifu says. To show the Taiwan-to-Yonaguni crossing could have been done, Kaifu starting to plan the “holistic reenactment” voyage in 2013. 

The team first built boats made of bundled bulrushes, similar in design to reed boats used by prehistoric peoples around the world; and then bamboo rafts, relying on traditional techniques used by Taiwan’s Amis tribe. Short-distance trial runs showed these crafts were slow and that currents pulled them off-course. The team concluded they were not suitable for long-distance voyages.

The voyagers will cross from Taiwan to Yonaguni in Japan, (red arrow) allowing a strong current to pull them northward as they paddle eastward. 

 

For their full-scale trip, Kaifu’s team—all seasoned ocean kayakers—will be paddling a log boat or dugout canoe of a type found in China and Japan dating back 8000 years. The team used simple stone axes, modeled on Paleolithic era archeological findings in Japan, to chop down a 1-meter-thick tree and then hew it into a 7-meter-long, 350-kilogram dugout. It proved lighter, more buoyant, and about 50% faster than the other craft. To emulate the ancients in other ways, the crew will not use modern navigational tools. Instead, the team includes a Maori man from New Zealand who can navigate by following the stars and judging winds and ocean swells.

Whatever happens, the results should be interpreted cautiously, says Helen Farr, an archeologist at the University of Southampton in the United Kingdom. Sea level would have been about 100 meters lower than it is now, she notes, and that could have affected the routes chosen by voyagers, among other things. Still, she praises the experiment, saying that it could “inform our understanding” of the challenges of early seafaring—and the skills, technologies, and social organization required for such a journey.

Even failure might be informative, says Robin Dennell, an archeologist at the University of Exeter in the United Kingdom who has studied the peopling of the Ryukyus. “It might show us how the islands were … not colonized,” he says, “and that might encourage a search for alternatives.” He also likes how the project is leading modern humans to “admire what people were able to do over 30,000 years ago.”

Posted in:

• Archaeology

doi:10.1126/science.aay6005

Dennis Normile