I did it by iSUP, by getting a train to Reading station to start, and a train back from Henley at the end, with only a short walk between each station and the river.
Conditions
very sunny day, but easterly wind meant a headwind at times going against the flow of the river so making it slightly choppy
Portage Notes
Sonning Lock is a straightforward portage (out before the lock gates and back in after the lock gates.
Shiplake Lock involves getting out before the lock gates, but crossing the island to get back in via a jetty on the weir stream
Marsh Lock involves a long portage (getting out to the right of the lock then crossing the lock gates and walking about 100m along the footbridge before getting back on the water.
