From Summit to Sea

It would be nice to say this adventure was based on careful reconnaissance and well reasoned forethought. It was not. Like many big ideas, this one emerged from some mates having a few beers. Within a couple of weeks, what started as idle discussion around a BBQ at the edge of the Tone River turned into a real adventure. Four gaijin would take a four-meter raft from near the summit of Tenjindaira in northern Gunma all the way to Tokyo Bay.

We picked a week to balance having sufficient snowmelt in the river with good weather and started our planning by tracing the route on Google maps. There were a few low dams on the river we knew from shorter trips we could run. In other cases, there were “rules” that would require us to portage the raft. Such is life. Armed with little more than this knowledge, we borrowed a boat from Canyons Outdoor Adventures in Minakami and were off.

The first day was all white water as we passed between many spectacular canyons with the occasional waterfall flowing into the river. This is familiar territory for anyone who has done commercial rafting in the upper Tonegawa. Given its narrowness, we tackled this section with paddles. By lunch, we had covered 40K and the river had widened, allowing us to switch to oars mounted on a frame lashed to the raft. As the day ended, we had covered 60 kilometers and pulled over to sleep on the edge of the river near Maebashi.

Although the first day had plenty of white water, the remaining 170 kilometers was mostly flat water, often accompanied by an afternoon head wind. As the raft only drew a few centimeters of water, the slightest breeze noticeably set back progress. On the third day, because of this wind, it would take a mammoth effort to cover the last 15K. It was a case of three strokes forward, two stroke lengths blown backward. Against this headwind, bringing the oars proved the best decision of the trip.

The final day dawned clear and fine, and we resumed the final 40 kilometers to the mouth of the Edo River and Tokyo Bay. As we entered this stretch, much of the greenery on either side gave way to industrial waterfront, and our main concern changed from fighting the wind to avoiding commercial ships. Even so, the remaining distance slipped by and, seven hours later, we were in Tokyo Bay and the “official” end to our trip.

This adventure was spawned over a beer and a BBQ and, since a few hours of daylight remained, we decided to tack on a few bonus kilometers and head across Tokyo Bay for a celebratory beer at Odaiba. Besides, it’s not every day you see a little yellow raft paddling under the Rainbow Bridge. 

In an almost Monty Python-like end, as we approached Odaiba, we heard all sorts of announcements and guys in suits yelling, “You cannot land here – go back.” Fortunately, our Japanese failed us sufficiently, allowing us to reach the beach, pick up the raft and walk 10 meters to the car park. At this point, beach police seemed lost as to what to do, or simply lost interest. After four days and 230 kilometers of paddling, only one question was left hanging in the air. “What to do next year?”

Summit to Sea

Day 1:
Near the headwaters of the Tone River to Maebashi
Distance: Approximately 60K 

All morning there was the distinct smell of sulfur from the onsen in the area. We bobbed along in white water and laboriously portaged one dam. We floated by small towns and farms until our first night on the riverbank just upstream from Maebashi.

Day 2:
Maebashi to near Hanyu City 
Distance: Approximately 60K

Numerous tributaries had been flowing into the river, which had grown substantially in volume, but was now broader and slower. White water gave way to slow currents and green flood plains opening on either side of the river.

Day 3:
near Hanyu City to Misato 
Distance: Approximately 60K

Fish were amazing—in both size and abundance— and the water surprisingly clear. At mid-day, we turned right into the Edo River. Huge banks of reeds floated past on either side, producing an eerie, remote, wilderness feel as we approached Tokyo.

Day 4:
Misato to Odaiba  
Distance: Approximately 50K

We could see the tops of tall buildings as we approached Tokyo Bay, but still green flood plains lined the sides of the river that teamed with fish. As we came to a floodgate 15K from Tokyo Bay, the greenery suddenly stopped, giving way to warehouses and industrial buildings. We entered the bay next to Tokyo Disneyland and the expanse of water reaching across to Odaiba seemed huge compared to the recent confines of the river.

Summit to Sea Participants: 
Jon, Doug and Mark are residents of Minakami, Gunma, where the idea for the trip was hatched. 

Jon Sparks:
Head of a property development company. Years ago, Jon rafted and kayaked the Grand Canyon unsupported for 21 days, so he had some idea what he was getting into on this trip.

Doug Smith:
Commercial real estate professional. Doug recently stepped up his fitness regimen and decided paddling for 10 hours a day would be good for his upper body strength.

Mark Baxter:
Finance industry professional. Mark and Jon recently rode the 200K from Tokyo to Minakami in a day. This was his first multi-day raft trip.

Gary Wong:
Finance industry professional. He had recently ridden with Doug from Tokyo to Kyoto, but this was his first (but, in his words, not his last) rafting experience.