6.45 AM, Embankment, SW15

With its sirens activated, a police car swings into Lower Richmond Road from Putney High Street. It turns right into Embankment and pulls up by the slipway leading down to the Thames. Two female officers climb out of the car and walk towards the railings, looking searchingly out across the river. Locating a tiny white craft emerging from beneath the bridge, they begin to wolf-whistle, trying to gain the attention if its proprietor. Nearing the shore in response to the official summons, it becomes clear that it is not a kayak or canoe, but a surfboard, and that its owner is navigating by laying on his belly and paddling with his hands.