We Swam Kelmscott to Grafton lock yesterday (River Thames) with a few friends and walking back, bumped into another group of swimmers.
For those that know who these were (or if that is you) - Shifford Lock (at Chimney Meadows) to Newbridge was the swim one of us shouted at you from the bank.
This gives you the complete swim ...we did one weekend (with Lunch in between).
It is about 1.5 to 2 hours swim at a gentle pace and if you make it a Sunday swim you can book ahead for a post Sunday Lunch when you finish. Makes it less of a bind for those that are drivers and not swimmers as they can wait in the pub.
It's a relatively remote swim in terms of civilization, so if you go make sure you can swim for that period of time or don't mind dragging yourself out and walking along the path. Oh and if you haven't been, the Rose Revived Pub is better than the Maybush Pub (Maytime?) which are on either side of the bridge.
You can get out before or after the bridge very easily.