The Thames Path is nice and easy to follow for most of the way but it's always handy to have a gps route of the path so you know whereabouts you are and how far you have to go to your destination. The files below are the complete route for the path and should be compatible with most GPS devices.
GPX File of the Thames Path (right click, Save As)
Memory Map mmo File of the Thames Path (right click, Save As)