> Once someone is reported to be in the water, invariably they must wait for the body to pop up.<p>Not quite invariably. The river police do rescue people who find themselves in the Thames. A couple of years ago I was walking between Southwark Bridge and Cannon Street Railway Bridge in the early evening when I noticed a group of people pointing towards something bobbing up and down in the middle of the river, in very turbulent conditions. It was someone who had fallen in. The river police arrived less than a minute or so later to rescue him. We walked down to the Bankside riverboat stop where the police dropped him off, conscious, and there was a waiting ambulance. I remember overhearing the police saying he had no idea how he fell in. I’d guess he was very lucky indeed and owed his life to the swift response of the police and whoever reported it.