It's past midday on a late May day in Suffolk and the sun is pouring down onto a calm sea. It's shining, for the first time this year, with that summer strength that makes you stop, to really take in the moment. It's perfect, here at the shoreline, not far from where the River Deben joins the sea, the beaches a mix of shingle and soft sand. 

Listen. 

Hear the mesmerisingly detailed and spatial sound which shallow waves make as they break and dissipate. Break, and dissipate.

A propeller plane. The grey outline of a container ship on the horizon. Sailing away. Under full steam, out into the North Sea.  With each new wave, its grey box-like outline shrinks, and recedes. A giant hulk, no bigger than a fingertip. A few waves more, until it dips out of sight.