The sun is shining, bleaching the whitewashed picnic tables along the promenade, making the sea sparkle. The shingle beach is steeply shelved in places, an avalanche of pebbles washed by the waves. The beach is busy but the water is utterly empty.

A dog called Basil whips across the sand, chasing into someone else’s picnic, his owners running after him screaming. The water is steely blue and blowing from the right. Beneath the surface it hardly shifts at all. It is colder than in the Isle of Sheppey, probably because of the lack of mud on the bottom to rise up and thicken the water.

Back on the beach, three men drag a rubber dingy up to the road, it’s rubber crunching across the stones. The water gets deep fast, the slash across my stomach cold at only a few paces in. The seagulls overhead are squawking and in the distance, picnickers are playing music. I swim back and forward, the waves riding up and into my face. Far away, if I turn my back to the land, I can see the white hulk of France on the horizon. The English Channel stretches away, surprisingly blue, a long flat ribbon. When I get out I dry in the sun and look across to a different country.

I’m raising money for the Alzheimer’s Society. Please sponsor me at http://www.justgiving.com/swimbonnieswim