Ahhhh! — that's the sound an overheated urbanite makes after cooling off in midsummer at Japan's finest whitewater rafting location, Tokushima Prefecture's Yoshino River. Its two gorges, the Oboke and Koboke, draw day-tripping beginners as well as more experienced enthusiasts, with their long stretches of cool, dark-green water lined with white limestone cliffs and large sections of frothy white-water action. I met Australian Mark Treston, operator of Happy Raft and 12-year resident of Japan, to learn about the area. "It's the best river in Japan by a long, long way," he said as we drove along winding roads high above the torrent.
"We have a really good rainy season and the rapids here rival any in the world," said Treston — great praise indeed, considering his guiding experience in Nepal, Australia, Canada and New Zealand. The river's headwaters are deep within Kochi Prefecture, held back by the Sameura dam, and while dams typically ruin rivers for rafting, Treston argued to the contrary.
"The Sameura dam actually improved the river for rafting," he said, pointing out previous high-water marks as we drove along the river. "In the past it used to get really high or low, but now we have daily releases, which means we have guaranteed water all through the summer."