Ōnaruto Bridge and Uzunomichi The sea is moving beneath the glass

I set off on a week-long summer trip around Shikoku. I boarded a ferry bound for Tokushima at Tokyo Port Ferry Terminal in Ariake, taking my red convertible with me, and got off in Tokushima the next afternoon. Today was day two, and my main reason for coming was to walk through the Ōnaruto Bridge's main girder and look down at the whirlpools through the glass floor.

The information at Uzunomichi said the whirlpools grow larger around high and low tide. The night before, I checked the tide table at my hotel and set out to arrive at the right time. I parked at Naruto Park, then walked about 5 minutes from the car park to the entrance. I rolled my denim jacket sleeves up a little and followed the path, breathing in the sea air. Before long, the massive girder of the Ōnaruto Bridge loomed overhead.

I'd thought this trip was just about seeing the bridge, but today I was going to walk through it. Inside Uzunomichi, the passage stretched far ahead, and I could see the sea through the mesh walls. A sea breeze slipped through the gaps, and the sound of waves rose from below. Unlike looking at the bridge from the car, the view changed at my own walking pace. That felt completely new.

As the glass floor came into view, my steps grew smaller without me thinking. I edged closer and looked down: the sea was right beneath my feet. The walkway was 45 m above the water. I'd come to see the distant view, but somehow what held my attention most was what lay directly below me. I pressed one hand to my chest over my white dress and tightened my grip on the handrail with the other.

I leaned against the handrail and took a closer look. Streaks of foam swirled across the surface, and the shapes that had looked round only moments ago came apart whenever I glanced away, curling up again somewhere else. I was so focused on tracking the changes that I was slow to notice someone coming up behind me. I hurried over to the edge of the passage.

I took a breather at one of the rest areas, then carried on down the walkway. There are four altogether. As I sat on a bench, the sound of the waves coming through the mesh felt closer than before. Every time I stopped, I remembered that I was out over the sea.

This walkway makes use of the space inside the bridge's main girder. The Uzunomichi guide included a staff member's behind-the-scenes story: this space had originally been set aside for the Shinkansen. I was walking over the sea through a place where trains were supposed to run. Thinking of it that way, the passage stretching ahead seemed to show me just how enormous the bridge was.

At the very end, the viewing room let me make a full loop with the sea in view. The Seto Inland Sea lay on one side, the Pacific Ocean on the other. As I walked along the windows, even the waves looked different on either side of the same strait. After all that time looking straight down, I finally lifted my eyes and took a slow lap, letting the breadth of the sea sink in.

On my way back, I stopped by the glass floor again. It was the same spot, but the shapes on the water had already changed completely. After I went outside, I walked for about 3 minutes to Eddy, an interactive museum about whirlpools and the bridge. After seeing the exhibits, I thought back to the whirlpools beneath the glass. The way their shapes came apart and curled back together seemed a little different to me.

Back at the car, I started looking for somewhere to have dinner. I found Ajidokoro Arashi, where they serve seafood set meals made with fish caught in the waters around Naruto and in the Seto Inland Sea. I wanted to taste fish from the waters I'd just been looking down at, with those streaks of foam still in my mind. I saved the restaurant on my map and started the engine.