"Get ready!" comes the call from Kato, our river guide who is standing at his post in the stern of our wooden longboat. My gaze snaps forward, scanning the waterway.
Up until this point, our cruise on the Arakawa (Ara River) in Saitama Prefecture has been an idyllic outing. Floating past imposing limestone cliffs set against a verdant background, I've let my eyes drift away from the water as it makes its way toward far-off Tokyo Bay to feast on the magnificent scenery. But ahead, white water swirls menacingly.
Kato gestures at the plastic sheets in the bottom of the boat and we scramble to pull them tightly around our bodies, and hunch away from the side of the boat, as the swirling eddies loom large in front of us.