A mile below the Roman arches of the Third Gate. There, the Gray Rush broadened into the salty salt marshes of the lower estuary, the river’s massive discharge rolled out across the sandbars in long, smooth, muscular swells. The wild white foam that had marked the morning’s crisis had smoothed out into a deep slate-colored current, thirty feet wide and twelve feet deep, gliding between the heavy granite stone retaining walls without a single eddy boiling back toward the town.
Ada Morland stood on the wet timber decking of the outer cutwater pier. Her navy overalls zipped was tight to her throat against the raw wind blowing in from the sea. Her left arm rested comfortably in the boiled linen sling Sister Merrow had fashioned. Meanwhile, her right hand held a brass tone check rod against the iron shoe of the center dolphin piling. The cold sea spray misted her glasses, but she didn’t bother to wipe them. Her attention was entirely focused on the rhythm shaking through the metal rod.
‘Sixteen point two feet per second,’ Ada announced, stepping back from the piling and letting the brass rod rest against her hip. ‘Smooth-flowing flow right down to the riverbed. There is no bubbling blast tearing at the timber shoes, and the gravel bar on the southern spit isn’t scouring out. The river is taking the deep channel exactly as your old charts laid it down.’
