I wondered how people had managed to fall at the fords when I first read the reports upthread, then I went and did it myself. At the weekend I used the Watlington-Market Drayton part of the WCW route to ride from Pangbourne to Stoke-on-Trent and back. Outward I noticed my front wheel slip slightly on the ford closest to Hanbury (the second on the way up). Coming back I unclipped and tried to cross slowly. I fell straight over on my left side as if on ice, bruising my elbow and knee, and leaving a large patch of green sort of algae gunk on my Carradice Barley. Maybe the secret is not to take it slowly and deliberately. I dismounted at the ford closer to Feckenham (that's what I thought too) and walked through, still slipping a little. Interestingly my shoes had been soaked through already on the way up at impromptu pedal-deep ford between Bletchingdon and Wooton, apparently caused by a burst water main.