I grew up in a weatherboard house in a mill town and like everyone else there I learnt to swim in the river. The sea was miles away but during big autumn swells a salty vapour drifted up the valley at the height of the treetops, and at night I lay awake as distant waves pummelled the shore. The earth beneath us seemed to hum. I used to get out of bed and lie on the karri floorboards and feel the rumble in my skull. There was a soothing monotony in the sound. It sang in every joist of the house, in my very bones, and during winter storms it began to sound more like artillery than mere water. I thought of the Blitz and my mother’s stories of all-night bombing raids, how she came up out of the ground with her parents to find entire streets gone. Some winter mornings I turned on the radio at breakfast half expecting to hear the news that whole slabs of the district had been lost to the sea—fences, roads, forest and pasture—all chewed off like so much cake.

My father was afraid of the sea a…