My revised plans based on Andrew's comments about sunset are to arrive at Walton Well Car Park at 18:15, leave there at 18:30 walk up the river to the starting point we used last Saturday (about 15 mins) and then to swim about 10-15 mins back to the bridge whilst admiring the large full moon across Port Meadow! (Weather permitting!)

Anybody there at the same time doing something similar I'd be pleased to see you and show you where I'm swimming.