The road across the flats

An original fictional travel passage set at an invented tidal crossing.

The island was plainly visible from the car park. It rose beyond the flats with three white houses on its shoulder and a tower that seemed no taller than a finger. I could see where I wanted to go. The notice beside the locked gate explained why seeing it was not the same as being able to reach it.

We had arrived early for the guided crossing. My father read the displayed times twice, then checked his watch as though one might persuade the other to change. Beyond the gate, a narrow road lay in the exposed mud. It was complete as far as I could see. That made the wait more irritating. A broken road would at least have offered a visible reason.

The guide arrived carrying a flask. She spoke to the six of us without hurrying, asking us to stay together and explaining that the surface could remain slippery after the water had withdrawn. She pointed out a shallow channel beside a marker. Until she did, I had taken its shining strip for more road. It was still moving.

When the gate opened, I expected the island to grow quickly. Instead, the flats widened around us. The houses remained small while the road under my feet acquired separate patches of sand, dark weed and pale shell. My father stopped checking his watch. He was watching where he put his boots.

Halfway across, the guide asked us to look back. The car park had become a row of bright scraps along the land. I could no longer pick out our car. The island was nearer, but the place we had left was unexpectedly remote.

At the far gate, I turned once more towards the crossing. From the car park, I had thought the road was an interval between two places. Walking it had filled the interval with things I had not known I would need to notice.

How does the writer show the narrator's understanding of the crossing developing? Support your answer with references to the passage.